test: generate the JWT test keys, drop application-dev.yml

The dev config held real keys. Local dev config now lives outside the repo; integration tests create a fresh Ed25519 keypair per run.

.gitea/workflows/publish-core.yml

@@ -0,0 +1,75 @@
+name: Build, Test & Push Core Service
+
+# Trigger the workflow
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  # ------------------------------------------------------------------
+  # JOB 1: Code integrity and quality gates (CI)
+  # ------------------------------------------------------------------
+  quality-check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v4
+
+      - name: Setup Java 25
+        uses: actions/setup-java@v4
+        with:
+          java-version: '25'
+          distribution: 'temurin'
+          # Automatically cache Maven dependencies to speed up builds
+          cache: 'maven'
+
+      - name: Make Maven Wrapper executable
+        # This fixes the "Permission denied" error on Linux runners
+        run: chmod +x mvnw
+
+      - name: Build and Test with Maven Wrapper
+        # Uses the wrapper to guarantee the correct Maven version
+        run: ./mvnw clean verify
+
+  # ------------------------------------------------------------------
+  # JOB 2: Docker Build & Push (CD)
+  # Runs only if 'quality-check' is successful and we are on branch main
+  # ------------------------------------------------------------------
+  docker:
+    needs: quality-check
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Prepare tag
+        id: prep
+        shell: bash
+        run: |
+          # Sanitize branch name for valid Docker tags
+          BRANCH="${GITHUB_REF_NAME}"
+          BRANCH="${BRANCH//\//-}"
+          BRANCH="$(echo "$BRANCH" | tr '[:upper:]' '[:lower:]')"
+          echo "branch=$BRANCH" >> "$GITHUB_OUTPUT"
+          echo "sha=${GITHUB_SHA::12}" >> "$GITHUB_OUTPUT"
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: git.andreas-dahm.eu
+          # Use your Gitea Secrets here
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.TOKEN_GITEA }}
+
+      - name: Build & Push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: |
+            git.andreas-dahm.eu/lobo_corp/tbp-core-service:${{ steps.prep.outputs.branch }}
+            git.andreas-dahm.eu/lobo_corp/tbp-core-service:${{ steps.prep.outputs.branch }}-${{ steps.prep.outputs.sha }}
+            git.andreas-dahm.eu/lobo_corp/tbp-core-service:latest

.gitignore

@@ -31,3 +31,10 @@ build/
 
 ### VS Code ###
 .vscode/
+
+### Local secrets ###
+.env
+
+### Local dev config, never committed ###
+application-dev.yml
+application-dev.yaml

.mvn/wrapper/maven-wrapper.properties

@@ -0,0 +1,3 @@
+wrapperVersion=3.3.4
+distributionType=only-script
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.9.14/apache-maven-3.9.14-bin.zip

Dockerfile

@@ -0,0 +1,35 @@
+# ------------------------------------------------------------------
+# STAGE 1: Build the application using Maven Wrapper
+# ------------------------------------------------------------------
+FROM eclipse-temurin:25-jdk-alpine AS builder
+
+WORKDIR /app
+
+# Copy the Maven wrapper and pom.xml first to cache dependencies
+COPY .mvn/ .mvn
+COPY mvnw pom.xml ./
+
+# Make the wrapper executable (just in case) and download dependencies
+RUN chmod +x mvnw
+RUN ./mvnw dependency:go-offline
+
+# Copy the actual source code and build the application (skip tests in Docker,
+# as they will be run by the Gitea Action before the build)
+COPY src ./src
+RUN ./mvnw clean package -DskipTests
+
+# ------------------------------------------------------------------
+# STAGE 2: Create the minimal runtime image
+# ------------------------------------------------------------------
+FROM eclipse-temurin:25-jre-alpine
+
+WORKDIR /app
+
+# Expose the port your Spring Boot app runs on
+EXPOSE 8090
+
+# Copy the compiled jar file from the builder stage
+COPY --from=builder /app/target/*.jar app.jar
+
+# Run the application
+ENTRYPOINT ["java", "-jar", "app.jar"]

compose.yaml

@@ -0,0 +1,10 @@
+services:
+  postgres:
+    image: postgres:17-alpine
+    container_name: tbp_core_db_local
+    ports:
+      - "5433:5432"
+    environment:
+      - POSTGRES_DB=tbp_core
+      - POSTGRES_USER=tbp_user
+      - POSTGRES_PASSWORD=local_secret_password

docker-compose.dev.yml

@@ -0,0 +1,22 @@
+# docker-compose.dev.yml
+services:
+  # ─────────────────────────────────────────────
+  # LOCAL DATABASE FOR DEVELOPMENT
+  # ─────────────────────────────────────────────
+  tbp-db-local:
+    image: postgres:17-alpine
+    container_name: tbp_db_local
+    restart: unless-stopped
+    ports:
+      # Map the container port 5432 to your local machine port 5432
+      - "5432:5432"
+    environment:
+      - POSTGRES_DB=tbp_core
+      - POSTGRES_USER=tbp_user
+      - POSTGRES_PASSWORD=${DB_PASSWORD}
+    volumes:
+      # Use a local volume to persist data across container restarts
+      - tbp_local_db_data:/var/lib/postgresql/data
+
+volumes:
+  tbp_local_db_data:

mvnw

@@ -0,0 +1,295 @@
+#!/bin/sh
+# ----------------------------------------------------------------------------
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+# ----------------------------------------------------------------------------
+
+# ----------------------------------------------------------------------------
+# Apache Maven Wrapper startup batch script, version 3.3.4
+#
+# Optional ENV vars
+# -----------------
+#   JAVA_HOME - location of a JDK home dir, required when download maven via java source
+#   MVNW_REPOURL - repo url base for downloading maven distribution
+#   MVNW_USERNAME/MVNW_PASSWORD - user and password for downloading maven
+#   MVNW_VERBOSE - true: enable verbose log; debug: trace the mvnw script; others: silence the output
+# ----------------------------------------------------------------------------
+
+set -euf
+[ "${MVNW_VERBOSE-}" != debug ] || set -x
+
+# OS specific support.
+native_path() { printf %s\\n "$1"; }
+case "$(uname)" in
+CYGWIN* | MINGW*)
+  [ -z "${JAVA_HOME-}" ] || JAVA_HOME="$(cygpath --unix "$JAVA_HOME")"
+  native_path() { cygpath --path --windows "$1"; }
+  ;;
+esac
+
+# set JAVACMD and JAVACCMD
+set_java_home() {
+  # For Cygwin and MinGW, ensure paths are in Unix format before anything is touched
+  if [ -n "${JAVA_HOME-}" ]; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+      # IBM's JDK on AIX uses strange locations for the executables
+      JAVACMD="$JAVA_HOME/jre/sh/java"
+      JAVACCMD="$JAVA_HOME/jre/sh/javac"
+    else
+      JAVACMD="$JAVA_HOME/bin/java"
+      JAVACCMD="$JAVA_HOME/bin/javac"
+
+      if [ ! -x "$JAVACMD" ] || [ ! -x "$JAVACCMD" ]; then
+        echo "The JAVA_HOME environment variable is not defined correctly, so mvnw cannot run." >&2
+        echo "JAVA_HOME is set to \"$JAVA_HOME\", but \"\$JAVA_HOME/bin/java\" or \"\$JAVA_HOME/bin/javac\" does not exist." >&2
+        return 1
+      fi
+    fi
+  else
+    JAVACMD="$(
+      'set' +e
+      'unset' -f command 2>/dev/null
+      'command' -v java
+    )" || :
+    JAVACCMD="$(
+      'set' +e
+      'unset' -f command 2>/dev/null
+      'command' -v javac
+    )" || :
+
+    if [ ! -x "${JAVACMD-}" ] || [ ! -x "${JAVACCMD-}" ]; then
+      echo "The java/javac command does not exist in PATH nor is JAVA_HOME set, so mvnw cannot run." >&2
+      return 1
+    fi
+  fi
+}
+
+# hash string like Java String::hashCode
+hash_string() {
+  str="${1:-}" h=0
+  while [ -n "$str" ]; do
+    char="${str%"${str#?}"}"
+    h=$(((h * 31 + $(LC_CTYPE=C printf %d "'$char")) % 4294967296))
+    str="${str#?}"
+  done
+  printf %x\\n $h
+}
+
+verbose() { :; }
+[ "${MVNW_VERBOSE-}" != true ] || verbose() { printf %s\\n "${1-}"; }
+
+die() {
+  printf %s\\n "$1" >&2
+  exit 1
+}
+
+trim() {
+  # MWRAPPER-139:
+  #   Trims trailing and leading whitespace, carriage returns, tabs, and linefeeds.
+  #   Needed for removing poorly interpreted newline sequences when running in more
+  #   exotic environments such as mingw bash on Windows.
+  printf "%s" "${1}" | tr -d '[:space:]'
+}
+
+scriptDir="$(dirname "$0")"
+scriptName="$(basename "$0")"
+
+# parse distributionUrl and optional distributionSha256Sum, requires .mvn/wrapper/maven-wrapper.properties
+while IFS="=" read -r key value; do
+  case "${key-}" in
+  distributionUrl) distributionUrl=$(trim "${value-}") ;;
+  distributionSha256Sum) distributionSha256Sum=$(trim "${value-}") ;;
+  esac
+done <"$scriptDir/.mvn/wrapper/maven-wrapper.properties"
+[ -n "${distributionUrl-}" ] || die "cannot read distributionUrl property in $scriptDir/.mvn/wrapper/maven-wrapper.properties"
+
+case "${distributionUrl##*/}" in
+maven-mvnd-*bin.*)
+  MVN_CMD=mvnd.sh _MVNW_REPO_PATTERN=/maven/mvnd/
+  case "${PROCESSOR_ARCHITECTURE-}${PROCESSOR_ARCHITEW6432-}:$(uname -a)" in
+  *AMD64:CYGWIN* | *AMD64:MINGW*) distributionPlatform=windows-amd64 ;;
+  :Darwin*x86_64) distributionPlatform=darwin-amd64 ;;
+  :Darwin*arm64) distributionPlatform=darwin-aarch64 ;;
+  :Linux*x86_64*) distributionPlatform=linux-amd64 ;;
+  *)
+    echo "Cannot detect native platform for mvnd on $(uname)-$(uname -m), use pure java version" >&2
+    distributionPlatform=linux-amd64
+    ;;
+  esac
+  distributionUrl="${distributionUrl%-bin.*}-$distributionPlatform.zip"
+  ;;
+maven-mvnd-*) MVN_CMD=mvnd.sh _MVNW_REPO_PATTERN=/maven/mvnd/ ;;
+*) MVN_CMD="mvn${scriptName#mvnw}" _MVNW_REPO_PATTERN=/org/apache/maven/ ;;
+esac
+
+# apply MVNW_REPOURL and calculate MAVEN_HOME
+# maven home pattern: ~/.m2/wrapper/dists/{apache-maven-<version>,maven-mvnd-<version>-<platform>}/<hash>
+[ -z "${MVNW_REPOURL-}" ] || distributionUrl="$MVNW_REPOURL$_MVNW_REPO_PATTERN${distributionUrl#*"$_MVNW_REPO_PATTERN"}"
+distributionUrlName="${distributionUrl##*/}"
+distributionUrlNameMain="${distributionUrlName%.*}"
+distributionUrlNameMain="${distributionUrlNameMain%-bin}"
+MAVEN_USER_HOME="${MAVEN_USER_HOME:-${HOME}/.m2}"
+MAVEN_HOME="${MAVEN_USER_HOME}/wrapper/dists/${distributionUrlNameMain-}/$(hash_string "$distributionUrl")"
+
+exec_maven() {
+  unset MVNW_VERBOSE MVNW_USERNAME MVNW_PASSWORD MVNW_REPOURL || :
+  exec "$MAVEN_HOME/bin/$MVN_CMD" "$@" || die "cannot exec $MAVEN_HOME/bin/$MVN_CMD"
+}
+
+if [ -d "$MAVEN_HOME" ]; then
+  verbose "found existing MAVEN_HOME at $MAVEN_HOME"
+  exec_maven "$@"
+fi
+
+case "${distributionUrl-}" in
+*?-bin.zip | *?maven-mvnd-?*-?*.zip) ;;
+*) die "distributionUrl is not valid, must match *-bin.zip or maven-mvnd-*.zip, but found '${distributionUrl-}'" ;;
+esac
+
+# prepare tmp dir
+if TMP_DOWNLOAD_DIR="$(mktemp -d)" && [ -d "$TMP_DOWNLOAD_DIR" ]; then
+  clean() { rm -rf -- "$TMP_DOWNLOAD_DIR"; }
+  trap clean HUP INT TERM EXIT
+else
+  die "cannot create temp dir"
+fi
+
+mkdir -p -- "${MAVEN_HOME%/*}"
+
+# Download and Install Apache Maven
+verbose "Couldn't find MAVEN_HOME, downloading and installing it ..."
+verbose "Downloading from: $distributionUrl"
+verbose "Downloading to: $TMP_DOWNLOAD_DIR/$distributionUrlName"
+
+# select .zip or .tar.gz
+if ! command -v unzip >/dev/null; then
+  distributionUrl="${distributionUrl%.zip}.tar.gz"
+  distributionUrlName="${distributionUrl##*/}"
+fi
+
+# verbose opt
+__MVNW_QUIET_WGET=--quiet __MVNW_QUIET_CURL=--silent __MVNW_QUIET_UNZIP=-q __MVNW_QUIET_TAR=''
+[ "${MVNW_VERBOSE-}" != true ] || __MVNW_QUIET_WGET='' __MVNW_QUIET_CURL='' __MVNW_QUIET_UNZIP='' __MVNW_QUIET_TAR=v
+
+# normalize http auth
+case "${MVNW_PASSWORD:+has-password}" in
+'') MVNW_USERNAME='' MVNW_PASSWORD='' ;;
+has-password) [ -n "${MVNW_USERNAME-}" ] || MVNW_USERNAME='' MVNW_PASSWORD='' ;;
+esac
+
+if [ -z "${MVNW_USERNAME-}" ] && command -v wget >/dev/null; then
+  verbose "Found wget ... using wget"
+  wget ${__MVNW_QUIET_WGET:+"$__MVNW_QUIET_WGET"} "$distributionUrl" -O "$TMP_DOWNLOAD_DIR/$distributionUrlName" || die "wget: Failed to fetch $distributionUrl"
+elif [ -z "${MVNW_USERNAME-}" ] && command -v curl >/dev/null; then
+  verbose "Found curl ... using curl"
+  curl ${__MVNW_QUIET_CURL:+"$__MVNW_QUIET_CURL"} -f -L -o "$TMP_DOWNLOAD_DIR/$distributionUrlName" "$distributionUrl" || die "curl: Failed to fetch $distributionUrl"
+elif set_java_home; then
+  verbose "Falling back to use Java to download"
+  javaSource="$TMP_DOWNLOAD_DIR/Downloader.java"
+  targetZip="$TMP_DOWNLOAD_DIR/$distributionUrlName"
+  cat >"$javaSource" <<-END
+	public class Downloader extends java.net.Authenticator
+	{
+	  protected java.net.PasswordAuthentication getPasswordAuthentication()
+	  {
+	    return new java.net.PasswordAuthentication( System.getenv( "MVNW_USERNAME" ), System.getenv( "MVNW_PASSWORD" ).toCharArray() );
+	  }
+	  public static void main( String[] args ) throws Exception
+	  {
+	    setDefault( new Downloader() );
+	    java.nio.file.Files.copy( java.net.URI.create( args[0] ).toURL().openStream(), java.nio.file.Paths.get( args[1] ).toAbsolutePath().normalize() );
+	  }
+	}
+	END
+  # For Cygwin/MinGW, switch paths to Windows format before running javac and java
+  verbose " - Compiling Downloader.java ..."
+  "$(native_path "$JAVACCMD")" "$(native_path "$javaSource")" || die "Failed to compile Downloader.java"
+  verbose " - Running Downloader.java ..."
+  "$(native_path "$JAVACMD")" -cp "$(native_path "$TMP_DOWNLOAD_DIR")" Downloader "$distributionUrl" "$(native_path "$targetZip")"
+fi
+
+# If specified, validate the SHA-256 sum of the Maven distribution zip file
+if [ -n "${distributionSha256Sum-}" ]; then
+  distributionSha256Result=false
+  if [ "$MVN_CMD" = mvnd.sh ]; then
+    echo "Checksum validation is not supported for maven-mvnd." >&2
+    echo "Please disable validation by removing 'distributionSha256Sum' from your maven-wrapper.properties." >&2
+    exit 1
+  elif command -v sha256sum >/dev/null; then
+    if echo "$distributionSha256Sum  $TMP_DOWNLOAD_DIR/$distributionUrlName" | sha256sum -c - >/dev/null 2>&1; then
+      distributionSha256Result=true
+    fi
+  elif command -v shasum >/dev/null; then
+    if echo "$distributionSha256Sum  $TMP_DOWNLOAD_DIR/$distributionUrlName" | shasum -a 256 -c >/dev/null 2>&1; then
+      distributionSha256Result=true
+    fi
+  else
+    echo "Checksum validation was requested but neither 'sha256sum' or 'shasum' are available." >&2
+    echo "Please install either command, or disable validation by removing 'distributionSha256Sum' from your maven-wrapper.properties." >&2
+    exit 1
+  fi
+  if [ $distributionSha256Result = false ]; then
+    echo "Error: Failed to validate Maven distribution SHA-256, your Maven distribution might be compromised." >&2
+    echo "If you updated your Maven version, you need to update the specified distributionSha256Sum property." >&2
+    exit 1
+  fi
+fi
+
+# unzip and move
+if command -v unzip >/dev/null; then
+  unzip ${__MVNW_QUIET_UNZIP:+"$__MVNW_QUIET_UNZIP"} "$TMP_DOWNLOAD_DIR/$distributionUrlName" -d "$TMP_DOWNLOAD_DIR" || die "failed to unzip"
+else
+  tar xzf${__MVNW_QUIET_TAR:+"$__MVNW_QUIET_TAR"} "$TMP_DOWNLOAD_DIR/$distributionUrlName" -C "$TMP_DOWNLOAD_DIR" || die "failed to untar"
+fi
+
+# Find the actual extracted directory name (handles snapshots where filename != directory name)
+actualDistributionDir=""
+
+# First try the expected directory name (for regular distributions)
+if [ -d "$TMP_DOWNLOAD_DIR/$distributionUrlNameMain" ]; then
+  if [ -f "$TMP_DOWNLOAD_DIR/$distributionUrlNameMain/bin/$MVN_CMD" ]; then
+    actualDistributionDir="$distributionUrlNameMain"
+  fi
+fi
+
+# If not found, search for any directory with the Maven executable (for snapshots)
+if [ -z "$actualDistributionDir" ]; then
+  # enable globbing to iterate over items
+  set +f
+  for dir in "$TMP_DOWNLOAD_DIR"/*; do
+    if [ -d "$dir" ]; then
+      if [ -f "$dir/bin/$MVN_CMD" ]; then
+        actualDistributionDir="$(basename "$dir")"
+        break
+      fi
+    fi
+  done
+  set -f
+fi
+
+if [ -z "$actualDistributionDir" ]; then
+  verbose "Contents of $TMP_DOWNLOAD_DIR:"
+  verbose "$(ls -la "$TMP_DOWNLOAD_DIR")"
+  die "Could not find Maven distribution directory in extracted archive"
+fi
+
+verbose "Found extracted Maven distribution directory: $actualDistributionDir"
+printf %s\\n "$distributionUrl" >"$TMP_DOWNLOAD_DIR/$actualDistributionDir/mvnw.url"
+mv -- "$TMP_DOWNLOAD_DIR/$actualDistributionDir" "$MAVEN_HOME" || [ -d "$MAVEN_HOME" ] || die "fail to move MAVEN_HOME"
+
+clean || :
+exec_maven "$@"

mvnw.cmd

@@ -0,0 +1,189 @@
+<# : batch portion
+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    http://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Apache Maven Wrapper startup batch script, version 3.3.4
+@REM
+@REM Optional ENV vars
+@REM   MVNW_REPOURL - repo url base for downloading maven distribution
+@REM   MVNW_USERNAME/MVNW_PASSWORD - user and password for downloading maven
+@REM   MVNW_VERBOSE - true: enable verbose log; others: silence the output
+@REM ----------------------------------------------------------------------------
+
+@IF "%__MVNW_ARG0_NAME__%"=="" (SET __MVNW_ARG0_NAME__=%~nx0)
+@SET __MVNW_CMD__=
+@SET __MVNW_ERROR__=
+@SET __MVNW_PSMODULEP_SAVE=%PSModulePath%
+@SET PSModulePath=
+@FOR /F "usebackq tokens=1* delims==" %%A IN (`powershell -noprofile "& {$scriptDir='%~dp0'; $script='%__MVNW_ARG0_NAME__%'; icm -ScriptBlock ([Scriptblock]::Create((Get-Content -Raw '%~f0'))) -NoNewScope}"`) DO @(
+  IF "%%A"=="MVN_CMD" (set __MVNW_CMD__=%%B) ELSE IF "%%B"=="" (echo %%A) ELSE (echo %%A=%%B)
+)
+@SET PSModulePath=%__MVNW_PSMODULEP_SAVE%
+@SET __MVNW_PSMODULEP_SAVE=
+@SET __MVNW_ARG0_NAME__=
+@SET MVNW_USERNAME=
+@SET MVNW_PASSWORD=
+@IF NOT "%__MVNW_CMD__%"=="" ("%__MVNW_CMD__%" %*)
+@echo Cannot start maven from wrapper >&2 && exit /b 1
+@GOTO :EOF
+: end batch / begin powershell #>
+
+$ErrorActionPreference = "Stop"
+if ($env:MVNW_VERBOSE -eq "true") {
+  $VerbosePreference = "Continue"
+}
+
+# calculate distributionUrl, requires .mvn/wrapper/maven-wrapper.properties
+$distributionUrl = (Get-Content -Raw "$scriptDir/.mvn/wrapper/maven-wrapper.properties" | ConvertFrom-StringData).distributionUrl
+if (!$distributionUrl) {
+  Write-Error "cannot read distributionUrl property in $scriptDir/.mvn/wrapper/maven-wrapper.properties"
+}
+
+switch -wildcard -casesensitive ( $($distributionUrl -replace '^.*/','') ) {
+  "maven-mvnd-*" {
+    $USE_MVND = $true
+    $distributionUrl = $distributionUrl -replace '-bin\.[^.]*$',"-windows-amd64.zip"
+    $MVN_CMD = "mvnd.cmd"
+    break
+  }
+  default {
+    $USE_MVND = $false
+    $MVN_CMD = $script -replace '^mvnw','mvn'
+    break
+  }
+}
+
+# apply MVNW_REPOURL and calculate MAVEN_HOME
+# maven home pattern: ~/.m2/wrapper/dists/{apache-maven-<version>,maven-mvnd-<version>-<platform>}/<hash>
+if ($env:MVNW_REPOURL) {
+  $MVNW_REPO_PATTERN = if ($USE_MVND -eq $False) { "/org/apache/maven/" } else { "/maven/mvnd/" }
+  $distributionUrl = "$env:MVNW_REPOURL$MVNW_REPO_PATTERN$($distributionUrl -replace "^.*$MVNW_REPO_PATTERN",'')"
+}
+$distributionUrlName = $distributionUrl -replace '^.*/',''
+$distributionUrlNameMain = $distributionUrlName -replace '\.[^.]*$','' -replace '-bin$',''
+
+$MAVEN_M2_PATH = "$HOME/.m2"
+if ($env:MAVEN_USER_HOME) {
+  $MAVEN_M2_PATH = "$env:MAVEN_USER_HOME"
+}
+
+if (-not (Test-Path -Path $MAVEN_M2_PATH)) {
+    New-Item -Path $MAVEN_M2_PATH -ItemType Directory | Out-Null
+}
+
+$MAVEN_WRAPPER_DISTS = $null
+if ((Get-Item $MAVEN_M2_PATH).Target[0] -eq $null) {
+  $MAVEN_WRAPPER_DISTS = "$MAVEN_M2_PATH/wrapper/dists"
+} else {
+  $MAVEN_WRAPPER_DISTS = (Get-Item $MAVEN_M2_PATH).Target[0] + "/wrapper/dists"
+}
+
+$MAVEN_HOME_PARENT = "$MAVEN_WRAPPER_DISTS/$distributionUrlNameMain"
+$MAVEN_HOME_NAME = ([System.Security.Cryptography.SHA256]::Create().ComputeHash([byte[]][char[]]$distributionUrl) | ForEach-Object {$_.ToString("x2")}) -join ''
+$MAVEN_HOME = "$MAVEN_HOME_PARENT/$MAVEN_HOME_NAME"
+
+if (Test-Path -Path "$MAVEN_HOME" -PathType Container) {
+  Write-Verbose "found existing MAVEN_HOME at $MAVEN_HOME"
+  Write-Output "MVN_CMD=$MAVEN_HOME/bin/$MVN_CMD"
+  exit $?
+}
+
+if (! $distributionUrlNameMain -or ($distributionUrlName -eq $distributionUrlNameMain)) {
+  Write-Error "distributionUrl is not valid, must end with *-bin.zip, but found $distributionUrl"
+}
+
+# prepare tmp dir
+$TMP_DOWNLOAD_DIR_HOLDER = New-TemporaryFile
+$TMP_DOWNLOAD_DIR = New-Item -Itemtype Directory -Path "$TMP_DOWNLOAD_DIR_HOLDER.dir"
+$TMP_DOWNLOAD_DIR_HOLDER.Delete() | Out-Null
+trap {
+  if ($TMP_DOWNLOAD_DIR.Exists) {
+    try { Remove-Item $TMP_DOWNLOAD_DIR -Recurse -Force | Out-Null }
+    catch { Write-Warning "Cannot remove $TMP_DOWNLOAD_DIR" }
+  }
+}
+
+New-Item -Itemtype Directory -Path "$MAVEN_HOME_PARENT" -Force | Out-Null
+
+# Download and Install Apache Maven
+Write-Verbose "Couldn't find MAVEN_HOME, downloading and installing it ..."
+Write-Verbose "Downloading from: $distributionUrl"
+Write-Verbose "Downloading to: $TMP_DOWNLOAD_DIR/$distributionUrlName"
+
+$webclient = New-Object System.Net.WebClient
+if ($env:MVNW_USERNAME -and $env:MVNW_PASSWORD) {
+  $webclient.Credentials = New-Object System.Net.NetworkCredential($env:MVNW_USERNAME, $env:MVNW_PASSWORD)
+}
+[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
+$webclient.DownloadFile($distributionUrl, "$TMP_DOWNLOAD_DIR/$distributionUrlName") | Out-Null
+
+# If specified, validate the SHA-256 sum of the Maven distribution zip file
+$distributionSha256Sum = (Get-Content -Raw "$scriptDir/.mvn/wrapper/maven-wrapper.properties" | ConvertFrom-StringData).distributionSha256Sum
+if ($distributionSha256Sum) {
+  if ($USE_MVND) {
+    Write-Error "Checksum validation is not supported for maven-mvnd. `nPlease disable validation by removing 'distributionSha256Sum' from your maven-wrapper.properties."
+  }
+  Import-Module $PSHOME\Modules\Microsoft.PowerShell.Utility -Function Get-FileHash
+  if ((Get-FileHash "$TMP_DOWNLOAD_DIR/$distributionUrlName" -Algorithm SHA256).Hash.ToLower() -ne $distributionSha256Sum) {
+    Write-Error "Error: Failed to validate Maven distribution SHA-256, your Maven distribution might be compromised. If you updated your Maven version, you need to update the specified distributionSha256Sum property."
+  }
+}
+
+# unzip and move
+Expand-Archive "$TMP_DOWNLOAD_DIR/$distributionUrlName" -DestinationPath "$TMP_DOWNLOAD_DIR" | Out-Null
+
+# Find the actual extracted directory name (handles snapshots where filename != directory name)
+$actualDistributionDir = ""
+
+# First try the expected directory name (for regular distributions)
+$expectedPath = Join-Path "$TMP_DOWNLOAD_DIR" "$distributionUrlNameMain"
+$expectedMvnPath = Join-Path "$expectedPath" "bin/$MVN_CMD"
+if ((Test-Path -Path $expectedPath -PathType Container) -and (Test-Path -Path $expectedMvnPath -PathType Leaf)) {
+  $actualDistributionDir = $distributionUrlNameMain
+}
+
+# If not found, search for any directory with the Maven executable (for snapshots)
+if (!$actualDistributionDir) {
+  Get-ChildItem -Path "$TMP_DOWNLOAD_DIR" -Directory | ForEach-Object {
+    $testPath = Join-Path $_.FullName "bin/$MVN_CMD"
+    if (Test-Path -Path $testPath -PathType Leaf) {
+      $actualDistributionDir = $_.Name
+    }
+  }
+}
+
+if (!$actualDistributionDir) {
+  Write-Error "Could not find Maven distribution directory in extracted archive"
+}
+
+Write-Verbose "Found extracted Maven distribution directory: $actualDistributionDir"
+Rename-Item -Path "$TMP_DOWNLOAD_DIR/$actualDistributionDir" -NewName $MAVEN_HOME_NAME | Out-Null
+try {
+  Move-Item -Path "$TMP_DOWNLOAD_DIR/$MAVEN_HOME_NAME" -Destination $MAVEN_HOME_PARENT | Out-Null
+} catch {
+  if (! (Test-Path -Path "$MAVEN_HOME" -PathType Container)) {
+    Write-Error "fail to move MAVEN_HOME"
+  }
+} finally {
+  try { Remove-Item $TMP_DOWNLOAD_DIR -Recurse -Force | Out-Null }
+  catch { Write-Warning "Cannot remove $TMP_DOWNLOAD_DIR" }
+}
+
+Write-Output "MVN_CMD=$MAVEN_HOME/bin/$MVN_CMD"

pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>4.1.0-M4</version>
+        <version>4.1.1</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
     <groupId>eu.andreasdahm.tbp</groupId>
@@ -16,7 +16,8 @@
         <java.version>25</java.version>
         <jwt.version>0.13.0</jwt.version>
         <testcontainers.version>1.21.4</testcontainers.version>
-        <archunit.version>1.4.1</archunit.version>
+        <archunit.version>1.5.0</archunit.version>
+        <resilience4j.version>2.4.0</resilience4j.version>
     </properties>
     <dependencies>
         <!-- Spring -->
@@ -40,10 +41,17 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-cache</artifactId>
         </dependency>
+        <!-- Rest Caching -->
         <dependency>
             <groupId>com.github.ben-manes.caffeine</groupId>
             <artifactId>caffeine</artifactId>
         </dependency>
+        <!-- Resilience: retry + rate limiter for outbound Steam calls -->
+        <dependency>
+            <groupId>io.github.resilience4j</groupId>
+            <artifactId>resilience4j-spring-boot4</artifactId>
+            <version>${resilience4j.version}</version>
+        </dependency>
         <!-- JWT -->
         <dependency>
             <groupId>io.jsonwebtoken</groupId>
@@ -75,6 +83,8 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-flyway</artifactId>
         </dependency>
+
+        <!-- Observability -->
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-actuator</artifactId>
@@ -84,6 +94,14 @@
             <artifactId>micrometer-registry-prometheus</artifactId>
             <scope>runtime</scope>
         </dependency>
+
+        <!-- testing -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-docker-compose</artifactId>
+            <scope>runtime</scope>
+            <optional>true</optional>
+        </dependency>
         <dependency>
             <groupId>org.postgresql</groupId>
             <artifactId>postgresql</artifactId>
@@ -99,11 +117,48 @@
             <artifactId>spring-boot-starter-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa-test</artifactId>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-security-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webmvc-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-devtools</artifactId>
+            <scope>runtime</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-testcontainers</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>postgresql</artifactId>
+            <scope>test</scope>
+            <version>${testcontainers.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${testcontainers.version}</version>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>com.tngtech.archunit</groupId>
             <artifactId>archunit-junit5</artifactId>
@@ -111,6 +166,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
     <build>
         <plugins>
             <plugin>

readme.md

@@ -0,0 +1,113 @@
+# To Be Played – Core Service
+
+Business service of **To Be Played**, a Steam backlog tracker. It syncs the user's Steam library, stores the backlog
+(status, rating, notes, priority), tracks playtime per day, syncs the wishlist and adds time-to-beat data from IGDB.
+
+To Be Played is split into three repositories:
+
+| Repository | Role |
+|---|---|
+| ToBePlayed-Auth | Users, login, settings, signs JWTs |
+| **ToBePlayed-Core** (this one) | Steam library, backlog, wishlist, stats; verifies JWTs |
+| ToBePlayed-Frontend | React single-page app |
+
+## Features
+
+- **Steam sync**: owned games, playtime and achievements through the Steam Web API. Manual sync plus a nightly
+  sync. Resilience4j retries and rate-limits every Steam call; Caffeine caches game counts and player summaries.
+- **Backlog**: status (`BACKLOG`, `PLAYING`, `FINISHED`, `COMPLETED` = 100 %, `DROPPED`), rating 1–5, notes, priority,
+  filters and sorting. "Pile of Shame" summary with a random suggestion of what to play.
+- **Playtime history**: one row per game and day, for the activity view and the "most played in the last two weeks"
+  dashboard banner.
+- **Wishlist**: synced from Steam with store price and discount.
+- **Time to beat**: story, extras and completionist hours from the IGDB API. Optional: without credentials the
+  feature is off and the rest works.
+- **Public profile data**: totals, status counts, games in progress and finished games with rating. Readable only
+  with a profile ticket issued by Auth. Never returns notes, priority or the Steam ID.
+
+## Authentication
+
+Core never issues tokens. It verifies Auth's EdDSA (Ed25519) JWTs with the public key only (`JWT_PUBLIC_KEY`) and
+reads `userId` and `steamId` from the claims. A token with a `typ` claim (for example a profile ticket) is rejected
+on normal endpoints; the profile ticket is accepted only by `GET /api/public/profiles/library` in the
+`X-Profile-Ticket` header.
+
+## API
+
+| Method | Path | Auth |
+|---|---|---|
+| `GET` | `/api/library/games`, `/api/library/games/{appid}` | JWT |
+| `PUT` | `/api/library/games/{appid}/backlog` | JWT |
+| `POST` | `/api/library/sync` | JWT |
+| `GET` | `/api/library/sync-status`, `/summary`, `/activity`, `/wishlist`, `/steam-profile`, `/games-count` | JWT |
+| `GET` | `/api/public/profiles/library` | profile ticket |
+| `GET` | `/api/stats/public` | public |
+
+## Tech stack
+
+- Java 25, Spring Boot 4.1 (Web MVC, Security, Data JPA, Validation, Cache with Caffeine), virtual threads
+- PostgreSQL 17, Flyway migrations
+- Resilience4j: retry and rate limiter for Steam, rate limiter for IGDB
+- JJWT with Ed25519 public key
+- Spring Boot Actuator + Micrometer (Prometheus)
+- Tests: JUnit 5, Testcontainers (PostgreSQL), ArchUnit
+- CI: Forgejo Actions, multi-stage Docker image
+
+## Architecture
+
+A modular monolith. Each module under `core_service.modules` is a vertical slice that could move to its own
+service later:
+
+| Module | Content |
+|---|---|
+| `library` | Sync, backlog, playtime history, wishlist, public profile data |
+| `stats` | Public numbers for the landing page |
+| `steam_adapter` | Steam Web API client |
+| `igdb_adapter` | IGDB client (Twitch OAuth) |
+
+Inside a module: `api` (controllers, DTOs), `service` (business logic), `domain` (JPA entities) and `repo`
+(Spring Data repositories). ArchUnit enforces cycle freedom, controller-to-repository direction, naming and module
+isolation in `src/test/java/core_service/architecture/ArchitectureTest.java`.
+
+## Run locally
+
+Needs Java 25 and Docker.
+
+```bash
+./mvnw spring-boot:run -Dspring-boot.run.profiles=dev
+```
+
+Spring Boot's Docker Compose support starts PostgreSQL from `compose.yaml`, Flyway applies the migrations, and the
+service listens on `http://localhost:8090`. Health: `/actuator/health`, metrics: `/actuator/prometheus`.
+
+In the `dev` profile a request without an `Authorization` header gets a dummy user, so the API is usable without a
+running Auth service.
+
+Configuration comes from environment variables:
+
+| Variable | Purpose |
+|---|---|
+| `JWT_PUBLIC_KEY` | Auth's Ed25519 public key, Base64 of the X.509 DER bytes |
+| `STEAM_API_KEY` | Steam Web API key |
+| `IGDB_CLIENT_ID`, `IGDB_CLIENT_SECRET` | Twitch app for IGDB (optional) |
+| `DB_PASSWORD` | Local PostgreSQL password |
+
+## Tests
+
+```bash
+./mvnw clean verify
+```
+
+Runs unit, WebMvc, persistence and integration tests plus the ArchUnit rules. Needs Docker for Testcontainers.
+
+## Roadmap
+
+- "What to play next" picker: time budget and mood on top of the current random suggestion.
+- Achievement summary per game and library-wide, "closest to 100 %".
+- Sale alerts for wishlist games.
+- Move `steam_adapter` DTOs out of `api`, then turn on strict module independence in ArchUnit.
+- Fetch the public key from a JWKS endpoint in Auth instead of an environment variable.
+
+## License
+
+All rights reserved. The source is public for reading only.

src/main/java/core_service/CoreServiceApplication.java

@@ -6,7 +6,8 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 @SpringBootApplication
 public class CoreServiceApplication {
 
-    public static void main(String[] args) {
+    static void main(String[] args) {
         SpringApplication.run(CoreServiceApplication.class, args);
     }
 }
+

src/main/java/core_service/configuration/AsyncConfig.java

@@ -0,0 +1,9 @@
+package core_service.configuration;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableAsync;
+
+@Configuration
+@EnableAsync
+public class AsyncConfig {
+}

src/main/java/core_service/configuration/CacheConfig.java

@@ -0,0 +1,26 @@
+package core_service.configuration;
+
+import com.github.benmanes.caffeine.cache.Caffeine;
+import org.springframework.cache.CacheManager;
+import org.springframework.cache.annotation.EnableCaching;
+import org.springframework.cache.caffeine.CaffeineCacheManager;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.Ordered;
+
+import java.util.concurrent.TimeUnit;
+
+@Configuration
+// Outside the resilience4j aspects, so a cache hit takes no Steam rate limiter permit.
+@EnableCaching(order = Ordered.HIGHEST_PRECEDENCE)
+public class CacheConfig {
+
+    @Bean
+    public CacheManager cacheManager() {
+        CaffeineCacheManager cacheManager = new CaffeineCacheManager("steamGameCount", "publicStats", "steamPlayerSummary");
+        cacheManager.setCaffeine(Caffeine.newBuilder()
+                .expireAfterWrite(10, TimeUnit.MINUTES)
+                .maximumSize(1000));
+        return cacheManager;
+    }
+}

src/main/java/core_service/configuration/SchedulingConfig.java

@@ -0,0 +1,9 @@
+package core_service.configuration;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.scheduling.annotation.EnableScheduling;
+
+@Configuration
+@EnableScheduling
+public class SchedulingConfig {
+}

src/main/java/core_service/configuration/security/DevJwtAuthenticationFilter.java

@@ -0,0 +1,87 @@
+package core_service.configuration.security;
+
+import core_service.shared.security.UserPrincipal;
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.NonNull;
+import org.springframework.context.annotation.Profile;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.context.SecurityContextHolder;
+import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import java.io.IOException;
+import java.util.Collections;
+
+/**
+ * Dev profile authentication filter.
+ * - If Authorization: Bearer ... is present and valid → builds principal from real JWT (so different users are isolated).
+ * - If no Authorization header → injects dummy principal so unauthenticated dev tools still work.
+ */
+@Component("jwtAuthenticationFilter")
+@Profile("dev")
+@RequiredArgsConstructor
+@Slf4j
+public class DevJwtAuthenticationFilter extends OncePerRequestFilter {
+
+    private final JwtService jwtService;
+
+    @Override
+    protected void doFilterInternal(
+            @NonNull HttpServletRequest request,
+            @NonNull HttpServletResponse response,
+            @NonNull FilterChain filterChain
+    ) throws ServletException, IOException {
+
+        if (SecurityContextHolder.getContext().getAuthentication() != null) {
+            filterChain.doFilter(request, response);
+            return;
+        }
+
+        UserPrincipal principal = principalFromJwt(request).orElseGet(this::dummyPrincipal);
+
+        UsernamePasswordAuthenticationToken authToken = new UsernamePasswordAuthenticationToken(
+                principal,
+                null,
+                Collections.emptyList()
+        );
+        authToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
+        SecurityContextHolder.getContext().setAuthentication(authToken);
+
+        filterChain.doFilter(request, response);
+    }
+
+    private java.util.Optional<UserPrincipal> principalFromJwt(HttpServletRequest request) {
+        String authHeader = request.getHeader("Authorization");
+        if (authHeader == null || !authHeader.startsWith("Bearer ")) {
+            return java.util.Optional.empty();
+        }
+        String jwt = authHeader.substring(7);
+        if (!jwtService.isTokenValid(jwt)) {
+            log.debug("Dev mode: invalid JWT, falling back to dummy principal");
+            return java.util.Optional.empty();
+        }
+        try {
+            String email = jwtService.extractEmail(jwt);
+            String userId = jwtService.extractUserId(jwt);
+            Long steamId = jwtService.extractSteamId(jwt);
+            if (email == null || userId == null) {
+                return java.util.Optional.empty();
+            }
+            return java.util.Optional.of(new UserPrincipal(userId, email, steamId));
+        } catch (Exception e) {
+            log.warn("Dev mode: JWT parsing failed: {}", e.getMessage());
+            return java.util.Optional.empty();
+        }
+    }
+
+    private UserPrincipal dummyPrincipal() {
+        log.trace("Dev mode: no JWT present, injecting dummy principal");
+        return new UserPrincipal("1", "dev@example.com", 76561198000000001L);
+    }
+}

src/main/java/core_service/configuration/security/JwtAuthenticationFilter.java

@@ -8,6 +8,7 @@ import jakarta.servlet.http.HttpServletResponse;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.jspecify.annotations.NonNull;
+import org.springframework.context.annotation.Profile;
 import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
 import org.springframework.security.core.context.SecurityContextHolder;
 import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
@@ -17,7 +18,8 @@ import org.springframework.web.filter.OncePerRequestFilter;
 import java.io.IOException;
 import java.util.Collections;
 
-@Component
+@Component("jwtAuthenticationFilter")
+@Profile("!dev")
 @RequiredArgsConstructor
 @Slf4j
 public class JwtAuthenticationFilter extends OncePerRequestFilter {
@@ -47,10 +49,11 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
         try {
             final String userEmail = jwtService.extractEmail(jwt);
             final String userId = jwtService.extractUserId(jwt);
+            final Long steamId = jwtService.extractSteamId(jwt);
 
             if (userEmail != null && userId != null && SecurityContextHolder.getContext().getAuthentication() == null) {
 
-                UserPrincipal principal = new UserPrincipal(userId, userEmail);
+                UserPrincipal principal = new UserPrincipal(userId, userEmail, steamId);
                 UsernamePasswordAuthenticationToken authToken = new UsernamePasswordAuthenticationToken(
                         principal,
                         null,
@@ -66,3 +69,4 @@ public class JwtAuthenticationFilter extends OncePerRequestFilter {
         filterChain.doFilter(request, response);
     }
 }
+

src/main/java/core_service/configuration/security/JwtConfig.java

@@ -11,5 +11,6 @@ import org.springframework.context.annotation.Configuration;
 @ConfigurationProperties(prefix = "security.jwt")
 public class JwtConfig {
 
-    private String secret;
+    /** Base64-encoded X.509 DER Ed25519 public key. Verify-only; private key lives in Auth. */
+    private String publicKey;
 }

src/main/java/core_service/configuration/security/JwtService.java

@@ -1,25 +1,42 @@
 package core_service.configuration.security;
 
-import core_service.shared.security.UserPrincipal;
+import core_service.shared.security.ProfileTicketVerifier;
 import io.jsonwebtoken.Jwts;
-import io.jsonwebtoken.security.Keys;
+import jakarta.annotation.PostConstruct;
 import org.springframework.stereotype.Service;
 
-import javax.crypto.SecretKey;
-import java.nio.charset.StandardCharsets;
+import java.security.KeyFactory;
+import java.security.PublicKey;
+import java.security.spec.X509EncodedKeySpec;
+import java.util.Base64;
+import java.util.Optional;
 
+/**
+ * Verifies JWTs issued by tbp-auth-service. Verify-only: holds the Ed25519 public key.
+ */
 @Service
-public class JwtService {
+public class JwtService implements ProfileTicketVerifier {
+
+    private static final String ED25519 = "Ed25519";
+    // Only non-login tokens carry this claim; isTokenValid rejects them.
+    private static final String TYPE_CLAIM = "typ";
+    private static final String PROFILE_TICKET_TYPE = "public-profile";
 
     private final JwtConfig jwtConfig;
+    private PublicKey publicKey;
 
     public JwtService(JwtConfig jwtConfig) {
         this.jwtConfig = jwtConfig;
     }
 
+    @PostConstruct
+    void init() {
+        this.publicKey = decodePublicKey(jwtConfig.getPublicKey());
+    }
+
     public String extractEmail(String token) {
         return Jwts.parser()
-                .verifyWith(getSigningKey())
+                .verifyWith(publicKey)
                 .build()
                 .parseSignedClaims(token)
                 .getPayload()
@@ -28,28 +45,61 @@ public class JwtService {
 
     public String extractUserId(String token) {
         return Jwts.parser()
-                .verifyWith(getSigningKey())
+                .verifyWith(publicKey)
                 .build()
                 .parseSignedClaims(token)
                 .getPayload()
                 .get("userId", String.class);
     }
 
+    public Long extractSteamId(String token) {
+        return Jwts.parser()
+                .verifyWith(publicKey)
+                .build()
+                .parseSignedClaims(token)
+                .getPayload()
+                .get("steamId", Long.class);
+    }
+
+    /**
+     * True for a login token with a valid signature. A profile ticket is signed with the same key, but is no login.
+     */
     public boolean isTokenValid(String token) {
         try {
-            Jwts.parser()
-                    .verifyWith(getSigningKey())
+            var claims = Jwts.parser()
+                    .verifyWith(publicKey)
                     .build()
-                    .parseSignedClaims(token);
-            return true;
+                    .parseSignedClaims(token)
+                    .getPayload();
+            return claims.get(TYPE_CLAIM) == null;
         } catch (Exception e) {
             return false;
         }
     }
 
-    private SecretKey getSigningKey() {
-        String secretKey = jwtConfig.getSecret();
-        byte[] keyBytes = secretKey.getBytes(StandardCharsets.UTF_8);
-        return Keys.hmacShaKeyFor(keyBytes);
+    @Override
+    public Optional<Long> verifyProfileTicket(String ticket) {
+        try {
+            var claims = Jwts.parser()
+                    .verifyWith(publicKey)
+                    .build()
+                    .parseSignedClaims(ticket)
+                    .getPayload();
+            if (!PROFILE_TICKET_TYPE.equals(claims.get(TYPE_CLAIM, String.class))) {
+                return Optional.empty();
+            }
+            return Optional.of(Long.parseLong(claims.get("profileUserId", String.class)));
+        } catch (Exception e) {
+            return Optional.empty();
+        }
+    }
+
+    private static PublicKey decodePublicKey(String base64X509Der) {
+        try {
+            byte[] keyBytes = Base64.getDecoder().decode(base64X509Der);
+            return KeyFactory.getInstance(ED25519).generatePublic(new X509EncodedKeySpec(keyBytes));
+        } catch (Exception e) {
+            throw new IllegalStateException("Failed to decode Ed25519 public key", e);
+        }
     }
 }

src/main/java/core_service/configuration/security/SecurityConfig.java

@@ -1,6 +1,7 @@
 package core_service.configuration.security;
 
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -14,23 +15,27 @@ import org.springframework.security.web.authentication.UsernamePasswordAuthentic
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.cors.CorsConfigurationSource;
 import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
+import org.springframework.web.filter.OncePerRequestFilter;
 
 import java.util.Arrays;
 import java.util.List;
 
 @Configuration
 @EnableWebSecurity
-@RequiredArgsConstructor
 public class SecurityConfig {
 
     private static final String[] WHITE_LIST_URLS = {
-            "/internal/**",           // Allow internal service communication
-            "/actuator/health",
-            "/actuator/prometheus",
-            "/error"
+            "/actuator/health",       // Docker health check; details are off
+            "/error",
+            "/api/stats/public",
+            "/api/public/**"          // Public profiles; PublicProfileController checks the ticket
     };
 
-    private final JwtAuthenticationFilter jwtAuthFilter;
+    private final OncePerRequestFilter jwtAuthFilter;
+
+    public SecurityConfig(@Qualifier("jwtAuthenticationFilter") OncePerRequestFilter jwtAuthFilter) {
+        this.jwtAuthFilter = jwtAuthFilter;
+    }
 
     @Value("${app.cors.allowed-origins}")
     private String[] allowedOrigins;
@@ -49,7 +54,7 @@ public class SecurityConfig {
     }
 
     @Bean
-    public SecurityFilterChain securityFilterChain(HttpSecurity http) throws Exception {
+    public SecurityFilterChain securityFilterChain(HttpSecurity http) {
         http
                 .csrf(AbstractHttpConfigurer::disable)
                 .cors(cors -> cors.configurationSource(corsConfigurationSource()))

src/main/java/core_service/modules/igdb_adapter/api/dto/response/IgdbResponses.java

@@ -0,0 +1,43 @@
+package core_service.modules.igdb_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+/**
+ * The parts of the Twitch token and IGDB v4 answers the adapter reads.
+ */
+public final class IgdbResponses {
+
+    private IgdbResponses() {
+    }
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Token(
+            @JsonProperty("access_token") String accessToken,
+            @JsonProperty("expires_in") Long expiresIn
+    ) {}
+
+    /**
+     * @param game the IGDB game id
+     * @param uid the id on the other service, here the Steam appid as a string
+     */
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record ExternalGame(
+            @JsonProperty("game") Long game,
+            @JsonProperty("uid") String uid
+    ) {}
+
+    /**
+     * Times in seconds; each can be missing.
+     *
+     * @param count how many players submitted a time
+     */
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record TimeToBeat(
+            @JsonProperty("game_id") Long gameId,
+            @JsonProperty("hastily") Integer hastily,
+            @JsonProperty("normally") Integer normally,
+            @JsonProperty("completely") Integer completely,
+            @JsonProperty("count") Integer count
+    ) {}
+}

src/main/java/core_service/modules/igdb_adapter/config/IgdbClientConfig.java

@@ -0,0 +1,20 @@
+package core_service.modules.igdb_adapter.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestClient;
+
+@Configuration
+public class IgdbClientConfig {
+
+    @Bean
+    public RestClient igdbRestClient(@Value("${app.igdb.base-url}") String baseUrl) {
+        return RestClient.builder().baseUrl(baseUrl).build();
+    }
+
+    @Bean
+    public RestClient twitchRestClient(@Value("${app.igdb.token-base-url}") String tokenBaseUrl) {
+        return RestClient.builder().baseUrl(tokenBaseUrl).build();
+    }
+}

src/main/java/core_service/modules/igdb_adapter/service/IgdbApiService.java

@@ -0,0 +1,176 @@
+package core_service.modules.igdb_adapter.service;
+
+import core_service.modules.igdb_adapter.api.dto.response.IgdbResponses;
+import io.github.resilience4j.ratelimiter.RateLimiter;
+import io.github.resilience4j.ratelimiter.RateLimiterRegistry;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.http.MediaType;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestClient;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+/**
+ * Time to beat from IGDB (api-docs.igdb.com), found by Steam appid. Needs a Twitch developer app; without its
+ * client id and secret the adapter is off and never calls out.
+ */
+@Service
+@Slf4j
+public class IgdbApiService {
+
+    /**
+     * @param hastilyMinutes to the credits; each value is null when IGDB has no data for it
+     */
+    public record TimeToBeat(Integer hastilyMinutes, Integer normallyMinutes, Integer completelyMinutes) {}
+
+    // IGDB answers at most 500 rows per query, and one Steam app can have more than one external_games row.
+    private static final int BATCH = 250;
+    private static final int LIMIT = 500;
+    private static final long STEAM_SOURCE = 1;
+    private static final Duration TOKEN_RENEW_BEFORE = Duration.ofHours(1);
+
+    private final RestClient igdbRestClient;
+    private final RestClient twitchRestClient;
+    private final String clientId;
+    private final String clientSecret;
+    // Per IGDB request, not per call: one call makes two requests per batch.
+    private final RateLimiter rateLimiter;
+
+    private String accessToken;
+    private Instant accessTokenRenewAt = Instant.EPOCH;
+
+    public IgdbApiService(@Qualifier("igdbRestClient") RestClient igdbRestClient,
+                          @Qualifier("twitchRestClient") RestClient twitchRestClient,
+                          @Value("${app.igdb.client-id:}") String clientId,
+                          @Value("${app.igdb.client-secret:}") String clientSecret,
+                          RateLimiterRegistry rateLimiterRegistry) {
+        this.igdbRestClient = igdbRestClient;
+        this.twitchRestClient = twitchRestClient;
+        this.clientId = clientId;
+        this.clientSecret = clientSecret;
+        this.rateLimiter = rateLimiterRegistry.rateLimiter("igdbApi");
+    }
+
+    public boolean isEnabled() {
+        return clientId != null && !clientId.isBlank() && clientSecret != null && !clientSecret.isBlank();
+    }
+
+    /**
+     * @return the times of the apps IGDB knows, apps without data are missing; empty when the adapter is off or a
+     * request failed, so the caller does not store "unknown" for apps it could not ask about
+     */
+    public Optional<Map<Long, TimeToBeat>> getTimeToBeat(Collection<Long> steamAppids) {
+        if (!isEnabled() || steamAppids.isEmpty()) {
+            return Optional.empty();
+        }
+        try {
+            List<Long> appids = List.copyOf(steamAppids);
+            Map<Long, TimeToBeat> result = new HashMap<>();
+            for (int from = 0; from < appids.size(); from += BATCH) {
+                result.putAll(getBatch(appids.subList(from, Math.min(from + BATCH, appids.size()))));
+            }
+            return Optional.of(result);
+        } catch (Exception e) {
+            log.error("Error communicating with IGDB for time to beat", e);
+            return Optional.empty();
+        }
+    }
+
+    private Map<Long, TimeToBeat> getBatch(List<Long> steamAppids) {
+        String uids = steamAppids.stream().map(id -> "\"" + id + "\"").collect(Collectors.joining(","));
+        IgdbResponses.ExternalGame[] externals = query("/external_games",
+                "fields game,uid; where external_game_source = " + STEAM_SOURCE + " & uid = (" + uids + "); limit " + LIMIT + ";",
+                IgdbResponses.ExternalGame[].class);
+        // Editions and re-releases: one IGDB game can have several Steam apps.
+        Map<Long, List<Long>> steamByIgdb = new HashMap<>();
+        for (IgdbResponses.ExternalGame external : externals) {
+            if (external.game() != null && external.uid() != null && external.uid().matches("\\d+")) {
+                steamByIgdb.computeIfAbsent(external.game(), game -> new ArrayList<>()).add(Long.parseLong(external.uid()));
+            }
+        }
+        if (steamByIgdb.isEmpty()) {
+            return Map.of();
+        }
+
+        String gameIds = steamByIgdb.keySet().stream().map(String::valueOf).collect(Collectors.joining(","));
+        IgdbResponses.TimeToBeat[] times = query("/game_time_to_beats",
+                "fields game_id,hastily,normally,completely,count; where game_id = (" + gameIds + "); limit " + LIMIT + ";",
+                IgdbResponses.TimeToBeat[].class);
+        // A Steam app linked to several IGDB games takes the time most players submitted.
+        Map<Long, TimeToBeat> result = new HashMap<>();
+        Arrays.stream(times)
+                .filter(time -> steamByIgdb.containsKey(time.gameId()))
+                .sorted(Comparator.comparing((IgdbResponses.TimeToBeat time) -> time.count() != null ? time.count() : 0).reversed())
+                .forEach(time -> steamByIgdb.get(time.gameId()).forEach(appid -> result.putIfAbsent(appid,
+                        new TimeToBeat(minutes(time.hastily()), minutes(time.normally()), minutes(time.completely())))));
+        return result;
+    }
+
+    private <T> T query(String path, String body, Class<T> type) {
+        String token = token();
+        RateLimiter.waitForPermission(rateLimiter);
+        T answer;
+        try {
+            answer = igdbRestClient.post()
+                    .uri(path)
+                    .header("Client-ID", clientId)
+                    .header("Authorization", "Bearer " + token)
+                    .contentType(MediaType.TEXT_PLAIN)
+                    .accept(MediaType.APPLICATION_JSON)
+                    .body(body)
+                    .retrieve()
+                    .body(type);
+        } catch (HttpClientErrorException.Unauthorized e) {
+            // Revoked, e.g. after a secret reset. The next call asks for a new token.
+            dropToken(token);
+            throw e;
+        }
+        if (answer == null) {
+            throw new IllegalStateException("IGDB " + path + " answered without a body");
+        }
+        return answer;
+    }
+
+    private synchronized String token() {
+        if (accessToken == null || Instant.now().isAfter(accessTokenRenewAt)) {
+            IgdbResponses.Token token = twitchRestClient.post()
+                    .uri(builder -> builder.path("/oauth2/token")
+                            .queryParam("client_id", clientId)
+                            .queryParam("client_secret", clientSecret)
+                            .queryParam("grant_type", "client_credentials")
+                            .build())
+                    .retrieve()
+                    .body(IgdbResponses.Token.class);
+            if (token == null || token.accessToken() == null) {
+                throw new IllegalStateException("Twitch answered without an access token");
+            }
+            long expiresIn = token.expiresIn() != null ? token.expiresIn() : 0;
+            accessToken = token.accessToken();
+            accessTokenRenewAt = Instant.now().plusSeconds(expiresIn).minus(TOKEN_RENEW_BEFORE);
+        }
+        return accessToken;
+    }
+
+    private synchronized void dropToken(String token) {
+        if (token.equals(accessToken)) {
+            accessToken = null;
+        }
+    }
+
+    private static Integer minutes(Integer seconds) {
+        return seconds != null && seconds > 0 ? Math.round(seconds / 60f) : null;
+    }
+}

src/main/java/core_service/modules/library/api/LibraryController.java

@@ -0,0 +1,177 @@
+package core_service.modules.library.api;
+
+import core_service.modules.library.api.dto.ActivityDto;
+import core_service.modules.library.api.dto.BacklogEntryDto;
+import core_service.modules.library.api.dto.GameDto;
+import core_service.modules.library.api.dto.LibrarySummaryDto;
+import core_service.modules.library.api.dto.PageDto;
+import core_service.modules.library.api.dto.SteamProfileDto;
+import core_service.modules.library.api.dto.SyncStatusDto;
+import core_service.modules.library.api.dto.WishlistDto;
+import core_service.modules.library.domain.GameStatus;
+import core_service.modules.library.service.BacklogService;
+import core_service.modules.library.service.GameDetailService;
+import core_service.modules.library.service.LibraryQueryService;
+import core_service.modules.library.service.LibrarySyncService;
+import core_service.modules.library.service.SteamProfileService;
+import core_service.modules.library.service.SyncCooldownException;
+import core_service.shared.security.UserPrincipal;
+import jakarta.validation.Valid;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Sort;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+import java.util.Set;
+
+@RestController
+@RequestMapping("/api/library")
+@RequiredArgsConstructor
+public class LibraryController {
+
+    private static final Set<Integer> ALLOWED_SIZES = Set.of(20, 40, 80);
+    private static final int DEFAULT_SIZE = 20;
+    private static final int MIN_ACTIVITY_DAYS = 7;
+    private static final int MAX_ACTIVITY_DAYS = 90;
+    private static final Set<String> SORTABLE_FIELDS = Set.of("playtimeMinutes", "firstSeenAt", "lastSeenAt", "appid", "rating", "priority");
+
+    private final LibrarySyncService syncService;
+    private final LibraryQueryService queryService;
+    private final GameDetailService gameDetailService;
+    private final BacklogService backlogService;
+    private final SteamProfileService steamProfileService;
+
+    @GetMapping("/games-count")
+    public ResponseEntity<?> getGamesCount(@AuthenticationPrincipal UserPrincipal principal) {
+        if (principal.steamId() == null) {
+            return ResponseEntity.ok(Map.of("count", 0, "hasSteamId", false));
+        }
+        Long userId = principal.getIdAsLong();
+        String steamId = String.valueOf(principal.steamId());
+        syncService.syncIfStale(userId, steamId);
+        long count = queryService.countOwnedGames(userId);
+        return ResponseEntity.ok(Map.of("count", count, "hasSteamId", true));
+    }
+
+    @GetMapping("/games")
+    public ResponseEntity<PageDto<GameDto>> getGames(
+            @AuthenticationPrincipal UserPrincipal principal,
+            @RequestParam(defaultValue = "0") int page,
+            @RequestParam(defaultValue = "20") int size,
+            @RequestParam(defaultValue = "playtimeMinutes,desc") String sort,
+            @RequestParam(required = false) GameStatus status,
+            @RequestParam(required = false) String q,
+            @RequestParam(required = false) Integer maxMinutes
+    ) {
+        if (principal.steamId() == null) {
+            return ResponseEntity.ok(new PageDto<>(java.util.List.of(), 0, DEFAULT_SIZE, 0, 0));
+        }
+        Long userId = principal.getIdAsLong();
+        String steamId = String.valueOf(principal.steamId());
+        syncService.syncIfStale(userId, steamId);
+
+        int safeSize = ALLOWED_SIZES.contains(size) ? size : DEFAULT_SIZE;
+        int safePage = Math.max(0, page);
+        Sort safeSort = parseSort(sort);
+        var dtoPage = queryService.listOwnedGames(userId, status, q, maxMinutes != null && maxMinutes > 0 ? maxMinutes : null, PageRequest.of(safePage, safeSize, safeSort));
+        return ResponseEntity.ok(PageDto.of(dtoPage));
+    }
+
+    private Sort parseSort(String sort) {
+        Sort fallback = Sort.by(Sort.Direction.DESC, "playtimeMinutes");
+        if (sort == null || sort.isBlank()) return fallback;
+        String[] parts = sort.split(",");
+        String field = parts[0].trim();
+        if (!SORTABLE_FIELDS.contains(field)) return fallback;
+        Sort.Direction dir = parts.length > 1 && "asc".equalsIgnoreCase(parts[1].trim())
+                ? Sort.Direction.ASC : Sort.Direction.DESC;
+        return Sort.by(dir, field);
+    }
+
+    @PostMapping("/sync")
+    public ResponseEntity<?> forceSync(@AuthenticationPrincipal UserPrincipal principal) {
+        if (principal.steamId() == null) {
+            return ResponseEntity.badRequest().body(Map.of("code", "NO_STEAM_ID", "message", "User has no Steam ID"));
+        }
+        try {
+            syncService.forceSync(principal.getIdAsLong(), String.valueOf(principal.steamId()));
+            return ResponseEntity.accepted().body(Map.of("status", "started"));
+        } catch (SyncCooldownException e) {
+            return ResponseEntity.status(HttpStatus.TOO_MANY_REQUESTS)
+                    .header(HttpHeaders.RETRY_AFTER, String.valueOf(e.getRetryAfterSeconds()))
+                    .body(Map.of(
+                            "code", "SYNC_COOLDOWN",
+                            "message", e.getMessage(),
+                            "retryAfterSeconds", e.getRetryAfterSeconds()));
+        }
+    }
+
+    @GetMapping("/games/{appid}")
+    public ResponseEntity<?> getGameDetail(@AuthenticationPrincipal UserPrincipal principal,
+                                           @PathVariable("appid") Long appid) {
+        if (principal.steamId() == null) {
+            return ResponseEntity.badRequest().body(Map.of("code", "NO_STEAM_ID", "message", "User has no Steam ID"));
+        }
+        Long userId = principal.getIdAsLong();
+        String steamId = String.valueOf(principal.steamId());
+        return gameDetailService.getGameDetail(userId, steamId, appid)
+                .<ResponseEntity<?>>map(ResponseEntity::ok)
+                .orElseGet(() -> ResponseEntity.status(HttpStatus.NOT_FOUND)
+                        .body(Map.of("code", "GAME_NOT_FOUND", "message", "Game not in user library")));
+    }
+
+    @PutMapping("/games/{appid}/backlog")
+    public ResponseEntity<?> updateBacklog(@AuthenticationPrincipal UserPrincipal principal,
+                                           @PathVariable("appid") Long appid,
+                                           @Valid @RequestBody BacklogEntryDto entry) {
+        return backlogService.update(principal.getIdAsLong(), appid, entry)
+                .<ResponseEntity<?>>map(ResponseEntity::ok)
+                .orElseGet(() -> ResponseEntity.status(HttpStatus.NOT_FOUND)
+                        .body(Map.of("code", "GAME_NOT_FOUND", "message", "Game not in user library")));
+    }
+
+    @GetMapping("/activity")
+    public ResponseEntity<ActivityDto> getActivity(@AuthenticationPrincipal UserPrincipal principal,
+                                                   @RequestParam(defaultValue = "30") int days) {
+        int safeDays = Math.clamp(days, MIN_ACTIVITY_DAYS, MAX_ACTIVITY_DAYS);
+        return ResponseEntity.ok(queryService.getActivity(principal.getIdAsLong(), safeDays));
+    }
+
+    @GetMapping("/wishlist")
+    public ResponseEntity<WishlistDto> getWishlist(@AuthenticationPrincipal UserPrincipal principal) {
+        return ResponseEntity.ok(queryService.getWishlist(principal.getIdAsLong()));
+    }
+
+    @GetMapping("/summary")
+    public ResponseEntity<LibrarySummaryDto> getSummary(@AuthenticationPrincipal UserPrincipal principal,
+                                                        @RequestParam(required = false) Long exclude) {
+        return ResponseEntity.ok(queryService.getSummary(principal.getIdAsLong(), exclude));
+    }
+
+    @GetMapping("/sync-status")
+    public ResponseEntity<SyncStatusDto> getSyncStatus(@AuthenticationPrincipal UserPrincipal principal) {
+        return queryService.getSyncStatus(principal.getIdAsLong())
+                .map(s -> new SyncStatusDto(
+                        s.getLastSyncedAt(),
+                        s.getLastSyncStatus() != null ? s.getLastSyncStatus().name() : null))
+                .map(ResponseEntity::ok)
+                .orElseGet(() -> ResponseEntity.ok(new SyncStatusDto(null, null)));
+    }
+
+    @GetMapping("/steam-profile")
+    public ResponseEntity<SteamProfileDto> getSteamProfile(@AuthenticationPrincipal UserPrincipal principal) {
+        return ResponseEntity.ok(steamProfileService.getProfile(principal.steamId()));
+    }
+}

src/main/java/core_service/modules/library/api/PublicProfileController.java

@@ -0,0 +1,35 @@
+package core_service.modules.library.api;
+
+import core_service.modules.library.service.LibraryQueryService;
+import core_service.shared.security.ProfileTicketVerifier;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Public, without login. Auth hands out the ticket only for a user whose profile is public, so this controller
+ * never needs to know the name or the privacy switch.
+ */
+@RestController
+@RequestMapping("/api/public/profiles")
+@RequiredArgsConstructor
+public class PublicProfileController {
+
+    private final LibraryQueryService queryService;
+    private final ProfileTicketVerifier profileTicketVerifier;
+
+    @GetMapping("/library")
+    public ResponseEntity<?> getPublicLibrary(@RequestHeader(value = "X-Profile-Ticket", required = false) String ticket) {
+        return (ticket == null ? Optional.<Long>empty() : profileTicketVerifier.verifyProfileTicket(ticket))
+                .<ResponseEntity<?>>map(userId -> ResponseEntity.ok(queryService.getPublicLibrary(userId)))
+                .orElseGet(() -> ResponseEntity.status(HttpStatus.UNAUTHORIZED)
+                        .body(Map.of("code", "INVALID_TICKET", "message", "Missing, invalid or expired profile ticket")));
+    }
+}

src/main/java/core_service/modules/library/api/dto/AchievementDto.java

@@ -0,0 +1,14 @@
+package core_service.modules.library.api.dto;
+
+import java.time.Instant;
+
+public record AchievementDto(
+        String apiName,
+        String displayName,
+        String description,
+        String iconUrl,
+        String iconGrayUrl,
+        boolean hidden,
+        boolean unlocked,
+        Instant unlockedAt
+) {}

src/main/java/core_service/modules/library/api/dto/ActivityDto.java

@@ -0,0 +1,15 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.DayMinutes;
+
+import java.util.List;
+
+/**
+ * @param days one entry per day, oldest first, also days without playtime
+ * @param recentGames up to 5 games by Steam's playtime of the last two weeks
+ */
+public record ActivityDto(
+        List<DayMinutes> days,
+        long totalMinutes,
+        List<RecentGameDto> recentGames
+) {}

src/main/java/core_service/modules/library/api/dto/BacklogEntryDto.java

@@ -0,0 +1,18 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GamePriority;
+import core_service.modules.library.domain.GameStatus;
+import jakarta.validation.constraints.Max;
+import jakarta.validation.constraints.Min;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
+
+/**
+ * Request and response of the backlog update. The request replaces all four fields; null clears an optional one.
+ */
+public record BacklogEntryDto(
+        @NotNull GameStatus status,
+        @Min(1) @Max(5) Integer rating,
+        @Size(max = 2000) String notes,
+        GamePriority priority
+) {}

src/main/java/core_service/modules/library/api/dto/GameDetailDto.java

@@ -0,0 +1,35 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GamePriority;
+import core_service.modules.library.domain.GameStatus;
+
+import java.time.Instant;
+import java.util.List;
+
+public record GameDetailDto(
+        Long appid,
+        String name,
+        String imgIconUrl,
+        int playtimeMinutes,
+        int playtime2Weeks,
+        Instant firstSeenAt,
+        Instant lastSeenAt,
+        GameStatus status,
+        Integer rating,
+        String notes,
+        GamePriority priority,
+        boolean hasAchievements,
+        boolean statsVisible,
+        int achievementsTotal,
+        int achievementsUnlocked,
+        int achievementsRemaining,
+        double completionPercent,
+        List<AchievementDto> achievements,
+        TimeToBeatDto timeToBeat
+) {
+
+    /**
+     * IGDB's averages in minutes; each is null when unknown.
+     */
+    public record TimeToBeatDto(Integer hastilyMinutes, Integer normallyMinutes, Integer completelyMinutes) {}
+}

src/main/java/core_service/modules/library/api/dto/GameDto.java

@@ -0,0 +1,18 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GamePriority;
+import core_service.modules.library.domain.GameStatus;
+
+/**
+ * @param timeToBeatMinutes IGDB's normal time to beat, null when unknown
+ */
+public record GameDto(
+        Long appid,
+        String name,
+        String imgIconUrl,
+        int playtimeMinutes,
+        GameStatus status,
+        Integer rating,
+        GamePriority priority,
+        Integer timeToBeatMinutes
+) {}

src/main/java/core_service/modules/library/api/dto/LibrarySummaryDto.java

@@ -0,0 +1,18 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GameStatus;
+
+import java.util.Map;
+
+/**
+ * @param byStatus has every status, also those with 0 games
+ * @param suggestion a random backlog game, null when the backlog is empty
+ * @param backlogMinutes normal time to beat of the backlog games IGDB knows; 0 when none or IGDB is off
+ */
+public record LibrarySummaryDto(
+        long total,
+        Map<GameStatus, Long> byStatus,
+        long neverPlayed,
+        GameDto suggestion,
+        long backlogMinutes
+) {}

src/main/java/core_service/modules/library/api/dto/PageDto.java

@@ -0,0 +1,22 @@
+package core_service.modules.library.api.dto;
+
+import org.springframework.data.domain.Page;
+
+import java.util.List;
+
+public record PageDto<T>(
+        List<T> content,
+        int page,
+        int size,
+        long totalElements,
+        int totalPages
+) {
+    public static <T> PageDto<T> of(Page<T> page) {
+        return new PageDto<>(
+                page.getContent(),
+                page.getNumber(),
+                page.getSize(),
+                page.getTotalElements(),
+                page.getTotalPages());
+    }
+}

src/main/java/core_service/modules/library/api/dto/PublicLibraryDto.java

@@ -0,0 +1,24 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GameStatus;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * What a public profile shows. Never notes, priority or anything that identifies the Steam account.
+ *
+ * @param byStatus has every status, also those with 0 games
+ * @param playing up to 8 games, most played first
+ * @param finished up to 12 FINISHED or COMPLETED games, best rated first
+ */
+public record PublicLibraryDto(
+        long totalGames,
+        long totalPlaytimeMinutes,
+        Map<GameStatus, Long> byStatus,
+        List<Game> playing,
+        List<Game> finished
+) {
+
+    public record Game(Long appid, String name, int playtimeMinutes, GameStatus status, Integer rating) {}
+}

src/main/java/core_service/modules/library/api/dto/RecentGameDto.java

@@ -0,0 +1,14 @@
+package core_service.modules.library.api.dto;
+
+import core_service.modules.library.domain.GameStatus;
+
+/**
+ * @param playtime2Weeks Steam's playtime of the last two weeks, in minutes
+ */
+public record RecentGameDto(
+        Long appid,
+        String name,
+        int playtimeMinutes,
+        int playtime2Weeks,
+        GameStatus status
+) {}

src/main/java/core_service/modules/library/api/dto/SteamProfileDto.java

@@ -0,0 +1,9 @@
+package core_service.modules.library.api.dto;
+
+/**
+ * The user's Steam name and avatar; both are null without a Steam ID or when Steam does not answer.
+ */
+public record SteamProfileDto(
+        String personaName,
+        String avatarUrl
+) {}

src/main/java/core_service/modules/library/api/dto/SyncStatusDto.java

@@ -0,0 +1,8 @@
+package core_service.modules.library.api.dto;
+
+import java.time.Instant;
+
+public record SyncStatusDto(
+        Instant lastSyncedAt,
+        String lastSyncStatus
+) {}

src/main/java/core_service/modules/library/api/dto/WishlistDto.java

@@ -0,0 +1,16 @@
+package core_service.modules.library.api.dto;
+
+import java.time.Instant;
+import java.util.List;
+
+/**
+ * @param games newest first, without the games the user owns
+ */
+public record WishlistDto(List<Game> games) {
+
+    /**
+     * @param price formatted by Steam, e.g. "7,49€"; null when the game has no price yet
+     * @param discountPct 0 when not on sale
+     */
+    public record Game(Long appid, String name, Instant addedAt, String price, String originalPrice, int discountPct) {}
+}

src/main/java/core_service/modules/library/domain/DayMinutes.java

@@ -0,0 +1,5 @@
+package core_service.modules.library.domain;
+
+import java.time.LocalDate;
+
+public record DayMinutes(LocalDate day, long minutes) {}

src/main/java/core_service/modules/library/domain/GameAchievementSchema.java

@@ -0,0 +1,54 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+@Entity
+@Table(name = "game_achievement_schema")
+@IdClass(GameAchievementSchemaId.class)
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class GameAchievementSchema {
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Id
+    @Column(name = "api_name", length = 256)
+    private String apiName;
+
+    @Column(name = "display_name", length = 512)
+    private String displayName;
+
+    @Column(name = "description", length = 2048)
+    private String description;
+
+    @Column(name = "icon_url", length = 512)
+    private String iconUrl;
+
+    @Column(name = "icon_gray_url", length = 512)
+    private String iconGrayUrl;
+
+    @Column(name = "hidden", nullable = false)
+    private boolean hidden;
+
+    public GameAchievementSchema(Long appid, String apiName, String displayName, String description,
+                                 String iconUrl, String iconGrayUrl, boolean hidden) {
+        this.appid = appid;
+        this.apiName = apiName;
+        this.displayName = displayName;
+        this.description = description;
+        this.iconUrl = iconUrl;
+        this.iconGrayUrl = iconGrayUrl;
+        this.hidden = hidden;
+    }
+}

src/main/java/core_service/modules/library/domain/GameAchievementSchemaId.java

@@ -0,0 +1,19 @@
+package core_service.modules.library.domain;
+
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.io.Serializable;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode
+public class GameAchievementSchemaId implements Serializable {
+    private Long appid;
+    private String apiName;
+}

src/main/java/core_service/modules/library/domain/GameAchievementSchemaMeta.java

@@ -0,0 +1,40 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "game_achievement_schema_meta")
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class GameAchievementSchemaMeta {
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "achievements_total", nullable = false)
+    private int achievementsTotal;
+
+    @Column(name = "has_schema", nullable = false)
+    private boolean hasSchema;
+
+    @Column(name = "refreshed_at", nullable = false)
+    private Instant refreshedAt;
+
+    public GameAchievementSchemaMeta(Long appid, int achievementsTotal, boolean hasSchema, Instant refreshedAt) {
+        this.appid = appid;
+        this.achievementsTotal = achievementsTotal;
+        this.hasSchema = hasSchema;
+        this.refreshedAt = refreshedAt;
+    }
+}

src/main/java/core_service/modules/library/domain/GamePriority.java

@@ -0,0 +1,7 @@
+package core_service.modules.library.domain;
+
+public enum GamePriority {
+    LOW,
+    MEDIUM,
+    HIGH
+}

src/main/java/core_service/modules/library/domain/GameStatus.java

@@ -0,0 +1,16 @@
+package core_service.modules.library.domain;
+
+public enum GameStatus {
+    BACKLOG,
+    PLAYING,
+    FINISHED,
+    COMPLETED,
+    DROPPED;
+
+    /**
+     * Status for a game the sync sees for the first time. Later syncs never change it.
+     */
+    public static GameStatus initialFor(int playtimeMinutes) {
+        return playtimeMinutes > 0 ? PLAYING : BACKLOG;
+    }
+}

src/main/java/core_service/modules/library/domain/GameTimeToBeat.java

@@ -0,0 +1,39 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.Instant;
+
+/**
+ * IGDB's time to beat of one Steam app; every time is null when IGDB has no data for it.
+ */
+@Entity
+@Table(name = "game_time_to_beat")
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+public class GameTimeToBeat {
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "hastily_minutes")
+    private Integer hastilyMinutes;
+
+    @Column(name = "normally_minutes")
+    private Integer normallyMinutes;
+
+    @Column(name = "completely_minutes")
+    private Integer completelyMinutes;
+
+    @Column(name = "fetched_at", nullable = false)
+    private Instant fetchedAt;
+}

src/main/java/core_service/modules/library/domain/PlaytimeDay.java

@@ -0,0 +1,38 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.LocalDate;
+
+/**
+ * Written only through {@code PlaytimeDayRepository.addMinutes}.
+ */
+@Entity
+@Table(name = "user_game_playtime_day")
+@IdClass(PlaytimeDayId.class)
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class PlaytimeDay {
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Id
+    @Column(name = "day")
+    private LocalDate day;
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "minutes", nullable = false)
+    private int minutes;
+}

src/main/java/core_service/modules/library/domain/PlaytimeDayId.java

@@ -0,0 +1,20 @@
+package core_service.modules.library.domain;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.io.Serializable;
+import java.time.LocalDate;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+@EqualsAndHashCode
+public class PlaytimeDayId implements Serializable {
+    private Long userId;
+    private LocalDate day;
+    private Long appid;
+}

src/main/java/core_service/modules/library/domain/StatusCount.java

@@ -0,0 +1,3 @@
+package core_service.modules.library.domain;
+
+public record StatusCount(GameStatus status, long count) {}

src/main/java/core_service/modules/library/domain/SteamGame.java

@@ -0,0 +1,40 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "steam_game")
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class SteamGame {
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "name", nullable = false, length = 512)
+    private String name;
+
+    @Column(name = "img_icon_url", length = 512)
+    private String imgIconUrl;
+
+    @Column(name = "last_seen_at", nullable = false)
+    private Instant lastSeenAt;
+
+    public SteamGame(Long appid, String name, String imgIconUrl, Instant lastSeenAt) {
+        this.appid = appid;
+        this.name = name;
+        this.imgIconUrl = imgIconUrl;
+        this.lastSeenAt = lastSeenAt;
+    }
+}

src/main/java/core_service/modules/library/domain/UserGame.java

@@ -0,0 +1,73 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.hibernate.annotations.DynamicUpdate;
+
+import java.time.Instant;
+
+@Entity
+// The sync and the backlog update run in separate transactions on the same row; each must write only its own columns.
+@DynamicUpdate
+@Table(name = "user_game")
+@IdClass(UserGameId.class)
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class UserGame {
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "playtime_minutes", nullable = false)
+    private int playtimeMinutes;
+
+    @Column(name = "playtime_2weeks", nullable = false)
+    private int playtime2Weeks;
+
+    @Column(name = "first_seen_at", nullable = false)
+    private Instant firstSeenAt;
+
+    @Column(name = "last_seen_at", nullable = false)
+    private Instant lastSeenAt;
+
+    @Column(name = "removed_at")
+    private Instant removedAt;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "status", nullable = false, length = 16)
+    private GameStatus status;
+
+    @Column(name = "rating")
+    private Integer rating;
+
+    @Column(name = "notes", length = 2000)
+    private String notes;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "priority", length = 8)
+    private GamePriority priority;
+
+    public UserGame(Long userId, Long appid, int playtimeMinutes, Instant firstSeenAt, Instant lastSeenAt) {
+        this.userId = userId;
+        this.appid = appid;
+        this.playtimeMinutes = playtimeMinutes;
+        this.firstSeenAt = firstSeenAt;
+        this.lastSeenAt = lastSeenAt;
+        this.status = GameStatus.initialFor(playtimeMinutes);
+    }
+}

src/main/java/core_service/modules/library/domain/UserGameAchievement.java

@@ -0,0 +1,48 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "user_game_achievement")
+@IdClass(UserGameAchievementId.class)
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class UserGameAchievement {
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Id
+    @Column(name = "api_name", length = 256)
+    private String apiName;
+
+    @Column(name = "unlocked", nullable = false)
+    private boolean unlocked;
+
+    @Column(name = "unlocked_at")
+    private Instant unlockedAt;
+
+    public UserGameAchievement(Long userId, Long appid, String apiName, boolean unlocked, Instant unlockedAt) {
+        this.userId = userId;
+        this.appid = appid;
+        this.apiName = apiName;
+        this.unlocked = unlocked;
+        this.unlockedAt = unlockedAt;
+    }
+}

src/main/java/core_service/modules/library/domain/UserGameAchievementId.java

@@ -0,0 +1,20 @@
+package core_service.modules.library.domain;
+
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.io.Serializable;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode
+public class UserGameAchievementId implements Serializable {
+    private Long userId;
+    private Long appid;
+    private String apiName;
+}

src/main/java/core_service/modules/library/domain/UserGameAchievementMeta.java

@@ -0,0 +1,47 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "user_game_achievement_meta")
+@IdClass(UserGameId.class)
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class UserGameAchievementMeta {
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    @Column(name = "refreshed_at", nullable = false)
+    private Instant refreshedAt;
+
+    @Column(name = "stats_visible", nullable = false)
+    private boolean statsVisible;
+
+    @Column(name = "achievements_unlocked", nullable = false)
+    private int achievementsUnlocked;
+
+    public UserGameAchievementMeta(Long userId, Long appid, Instant refreshedAt, boolean statsVisible, int achievementsUnlocked) {
+        this.userId = userId;
+        this.appid = appid;
+        this.refreshedAt = refreshedAt;
+        this.statsVisible = statsVisible;
+        this.achievementsUnlocked = achievementsUnlocked;
+    }
+}

src/main/java/core_service/modules/library/domain/UserGameId.java

@@ -0,0 +1,19 @@
+package core_service.modules.library.domain;
+
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.io.Serializable;
+
+@Getter
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
+@EqualsAndHashCode
+public class UserGameId implements Serializable {
+    private Long userId;
+    private Long appid;
+}

src/main/java/core_service/modules/library/domain/UserSteamSync.java

@@ -0,0 +1,49 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.EnumType;
+import jakarta.persistence.Enumerated;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.Instant;
+
+@Entity
+@Table(name = "user_steam_sync")
+@Getter
+@Setter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+public class UserSteamSync {
+
+    public enum Status { OK, FAILED, RUNNING }
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Column(name = "steam_id", nullable = false, length = 32)
+    private String steamId;
+
+    @Column(name = "last_synced_at")
+    private Instant lastSyncedAt;
+
+    @Enumerated(EnumType.STRING)
+    @Column(name = "last_sync_status", length = 16)
+    private Status lastSyncStatus;
+
+    @Column(name = "history_steam_id", length = 32)
+    private String historySteamId;
+
+    @Column(name = "user_seen_at")
+    private Instant userSeenAt;
+
+    public UserSteamSync(Long userId, String steamId) {
+        this.userId = userId;
+        this.steamId = steamId;
+    }
+}

src/main/java/core_service/modules/library/domain/WishlistGame.java

@@ -0,0 +1,50 @@
+package core_service.modules.library.domain;
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+import jakarta.persistence.Table;
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.time.Instant;
+
+/**
+ * @see core_service.modules.library.repo.WishlistGameRepository
+ */
+@Entity
+@Table(name = "wishlist_game")
+@IdClass(WishlistGameId.class)
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+public class WishlistGame {
+
+    @Id
+    @Column(name = "user_id")
+    private Long userId;
+
+    @Id
+    @Column(name = "appid")
+    private Long appid;
+
+    // Null when the store does not know the app (any more).
+    @Column(name = "name", length = 512)
+    private String name;
+
+    @Column(name = "added_at")
+    private Instant addedAt;
+
+    // Formatted by Steam for the store country, e.g. "7,49€". Null for an app without a price.
+    @Column(name = "price", length = 32)
+    private String price;
+
+    @Column(name = "original_price", length = 32)
+    private String originalPrice;
+
+    @Column(name = "discount_pct", nullable = false)
+    private int discountPct;
+}

src/main/java/core_service/modules/library/domain/WishlistGameId.java

@@ -0,0 +1,18 @@
+package core_service.modules.library.domain;
+
+import lombok.AccessLevel;
+import lombok.AllArgsConstructor;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import java.io.Serializable;
+
+@Getter
+@NoArgsConstructor(access = AccessLevel.PROTECTED)
+@AllArgsConstructor
+@EqualsAndHashCode
+public class WishlistGameId implements Serializable {
+    private Long userId;
+    private Long appid;
+}

src/main/java/core_service/modules/library/repo/GameAchievementSchemaMetaRepository.java

@@ -0,0 +1,7 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.GameAchievementSchemaMeta;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface GameAchievementSchemaMetaRepository extends JpaRepository<GameAchievementSchemaMeta, Long> {
+}

src/main/java/core_service/modules/library/repo/GameAchievementSchemaRepository.java

@@ -0,0 +1,14 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.GameAchievementSchema;
+import core_service.modules.library.domain.GameAchievementSchemaId;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface GameAchievementSchemaRepository extends JpaRepository<GameAchievementSchema, GameAchievementSchemaId> {
+
+    List<GameAchievementSchema> findByAppid(Long appid);
+
+    void deleteByAppid(Long appid);
+}

src/main/java/core_service/modules/library/repo/GameTimeToBeatRepository.java

@@ -0,0 +1,33 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.GameTimeToBeat;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.Instant;
+import java.util.Collection;
+import java.util.Set;
+
+public interface GameTimeToBeatRepository extends JpaRepository<GameTimeToBeat, Long> {
+
+    @Query("select t.appid from GameTimeToBeat t where t.appid in :appids and t.fetchedAt > :since")
+    Set<Long> findFreshAppids(@Param("appids") Collection<Long> appids, @Param("since") Instant since);
+
+    // An upsert, not save(): two users' syncs can store the same new app at the same time.
+    @Modifying
+    @Transactional
+    @Query(value = "insert into game_time_to_beat (appid, hastily_minutes, normally_minutes, completely_minutes, fetched_at) " +
+                   "values (:appid, :hastily, :normally, :completely, :fetchedAt) " +
+                   "on conflict (appid) do update set hastily_minutes = excluded.hastily_minutes, " +
+                   "normally_minutes = excluded.normally_minutes, completely_minutes = excluded.completely_minutes, " +
+                   "fetched_at = excluded.fetched_at",
+           nativeQuery = true)
+    void upsert(@Param("appid") Long appid,
+                @Param("hastily") Integer hastilyMinutes,
+                @Param("normally") Integer normallyMinutes,
+                @Param("completely") Integer completelyMinutes,
+                @Param("fetchedAt") Instant fetchedAt);
+}

src/main/java/core_service/modules/library/repo/PlaytimeDayRepository.java

@@ -0,0 +1,31 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.DayMinutes;
+import core_service.modules.library.domain.PlaytimeDay;
+import core_service.modules.library.domain.PlaytimeDayId;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDate;
+import java.util.List;
+
+public interface PlaytimeDayRepository extends JpaRepository<PlaytimeDay, PlaytimeDayId> {
+
+    @Modifying
+    @Transactional
+    @Query(value = "insert into user_game_playtime_day (user_id, day, appid, minutes) values (:userId, :day, :appid, :minutes) " +
+                   "on conflict (user_id, day, appid) do update set minutes = user_game_playtime_day.minutes + excluded.minutes",
+            nativeQuery = true)
+    void addMinutes(@Param("userId") Long userId, @Param("appid") Long appid,
+                    @Param("day") LocalDate day, @Param("minutes") int minutes);
+
+    /**
+     * Only days with playtime; the caller fills the gaps.
+     */
+    @Query("select new core_service.modules.library.domain.DayMinutes(p.day, sum(p.minutes)) from PlaytimeDay p " +
+           "where p.userId = :userId and p.day >= :from group by p.day order by p.day")
+    List<DayMinutes> minutesPerDay(@Param("userId") Long userId, @Param("from") LocalDate from);
+}

src/main/java/core_service/modules/library/repo/SteamGameRepository.java

@@ -0,0 +1,7 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.SteamGame;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface SteamGameRepository extends JpaRepository<SteamGame, Long> {
+}

src/main/java/core_service/modules/library/repo/UserGameAchievementMetaRepository.java

@@ -0,0 +1,12 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.UserGameAchievementMeta;
+import core_service.modules.library.domain.UserGameId;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface UserGameAchievementMetaRepository extends JpaRepository<UserGameAchievementMeta, UserGameId> {
+
+    Optional<UserGameAchievementMeta> findByUserIdAndAppid(Long userId, Long appid);
+}

src/main/java/core_service/modules/library/repo/UserGameAchievementRepository.java

@@ -0,0 +1,14 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.UserGameAchievement;
+import core_service.modules.library.domain.UserGameAchievementId;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface UserGameAchievementRepository extends JpaRepository<UserGameAchievement, UserGameAchievementId> {
+
+    List<UserGameAchievement> findByUserIdAndAppid(Long userId, Long appid);
+
+    void deleteByUserIdAndAppid(Long userId, Long appid);
+}

src/main/java/core_service/modules/library/repo/UserGameRepository.java

@@ -0,0 +1,109 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.GameStatus;
+import core_service.modules.library.domain.StatusCount;
+import core_service.modules.library.domain.UserGame;
+import core_service.modules.library.domain.UserGameId;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.jpa.domain.JpaSort;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.time.Instant;
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+import java.util.Optional;
+
+public interface UserGameRepository extends JpaRepository<UserGame, UserGameId> {
+
+    List<UserGame> findByUserIdAndRemovedAtIsNull(Long userId);
+
+    long countByUserIdAndRemovedAtIsNull(Long userId);
+
+    @Query("select coalesce(sum(ug.playtimeMinutes), 0) from UserGame ug where ug.userId = :userId and ug.removedAt is null")
+    long sumPlaytime(@Param("userId") Long userId);
+
+    List<UserGame> findByUserIdAndRemovedAtIsNullAndStatusIn(Long userId, Collection<GameStatus> statuses, Pageable pageable);
+
+    List<UserGame> findTop5ByUserIdAndRemovedAtIsNullAndPlaytime2WeeksGreaterThanOrderByPlaytime2WeeksDesc(
+            Long userId, int playtime2Weeks);
+
+    long countByUserIdAndRemovedAtIsNullAndPlaytimeMinutes(Long userId, int playtimeMinutes);
+
+    @Query("select new core_service.modules.library.domain.StatusCount(ug.status, count(ug)) from UserGame ug " +
+           "where ug.userId = :userId and ug.removedAt is null group by ug.status")
+    List<StatusCount> countByStatus(@Param("userId") Long userId);
+
+    /**
+     * @param excludeAppid never picked; -1 excludes nothing
+     */
+    @Query(value = "select * from user_game where user_id = :userId and removed_at is null and status = 'BACKLOG' " +
+                   "and appid <> :excludeAppid order by random() limit 1", nativeQuery = true)
+    Optional<UserGame> findRandomBacklogGame(@Param("userId") Long userId, @Param("excludeAppid") long excludeAppid);
+
+    /**
+     * @param status null for every status
+     * @param namePattern a {@link #containsPattern} result, null for every name
+     * @param maxMinutes only games whose normal time to beat is known and at most this; null for every game
+     */
+    @Query("select ug from UserGame ug join SteamGame sg on sg.appid = ug.appid " +
+           "where ug.userId = :userId and ug.removedAt is null " +
+           "and (:status is null or ug.status = :status) " +
+           "and (:namePattern is null or lower(sg.name) like :namePattern escape '\\') " +
+           "and (:maxMinutes is null or exists (select 1 from GameTimeToBeat t " +
+           "     where t.appid = ug.appid and t.normallyMinutes <= :maxMinutes))")
+    Page<UserGame> findOwnedGames(@Param("userId") Long userId,
+                                  @Param("status") GameStatus status,
+                                  @Param("namePattern") String namePattern,
+                                  @Param("maxMinutes") Integer maxMinutes,
+                                  Pageable pageable);
+
+    /**
+     * Normal time to beat of the user's backlog, only games IGDB has data for.
+     */
+    @Query("select coalesce(sum(t.normallyMinutes), 0) from UserGame ug join GameTimeToBeat t on t.appid = ug.appid " +
+           "where ug.userId = :userId and ug.removedAt is null " +
+           "and ug.status = core_service.modules.library.domain.GameStatus.BACKLOG")
+    long sumBacklogMinutes(@Param("userId") Long userId);
+
+    /**
+     * Makes a {@link #findOwnedGames} sort stable and meaningful: games without a rating or priority come last
+     * in both directions, priority sorts by HIGH, MEDIUM, LOW (the enum names would sort alphabetically), and
+     * appid breaks every tie so pages do not repeat or skip games.
+     */
+    static Sort querySort(Sort requested) {
+        Sort result = Sort.unsorted();
+        for (Sort.Order order : requested) {
+            result = result.and(switch (order.getProperty()) {
+                case "rating" -> Sort.by(order.nullsLast());
+                case "priority" -> Sort.by(JpaSort.unsafe(order.getDirection(),
+                        "(case ug.priority when 'HIGH' then 3 when 'MEDIUM' then 2 when 'LOW' then 1 end)")
+                        .iterator().next().nullsLast());
+                default -> Sort.by(order);
+            });
+        }
+        return result.and(Sort.by("appid"));
+    }
+
+    /**
+     * Case-insensitive "contains" pattern for {@link #findOwnedGames}; % and _ in the query match literally.
+     */
+    static String containsPattern(String query) {
+        if (query == null || query.isBlank()) return null;
+        String escaped = query.trim().toLowerCase(Locale.ROOT)
+                .replace("\\", "\\\\").replace("%", "\\%").replace("_", "\\_");
+        return "%" + escaped + "%";
+    }
+
+    @Modifying
+    @Query("update UserGame ug set ug.removedAt = :now " +
+           "where ug.userId = :userId and ug.lastSeenAt < :syncStartedAt and ug.removedAt is null")
+    int softDeleteMissingSince(@Param("userId") Long userId,
+                               @Param("syncStartedAt") Instant syncStartedAt,
+                               @Param("now") Instant now);
+}

src/main/java/core_service/modules/library/repo/UserSteamSyncRepository.java

@@ -0,0 +1,57 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.UserSteamSync;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.Instant;
+import java.util.List;
+
+public interface UserSteamSyncRepository extends JpaRepository<UserSteamSync, Long> {
+
+    /**
+     * Atomic claim-run upsert. Returns 1 if this caller successfully claimed the run
+     * (row created, or existing row was not RUNNING / RUNNING marker stale).
+     * Returns 0 if another sync is already in flight — caller must skip.
+     */
+    @Modifying
+    @Query(value = """
+            INSERT INTO user_steam_sync (user_id, steam_id, last_sync_status)
+            VALUES (:userId, :steamId, 'RUNNING')
+            ON CONFLICT (user_id) DO UPDATE
+            SET steam_id = EXCLUDED.steam_id,
+                last_sync_status = 'RUNNING'
+            WHERE user_steam_sync.last_sync_status <> 'RUNNING'
+               OR user_steam_sync.last_synced_at IS NULL
+               OR user_steam_sync.last_synced_at < :runningStaleBefore
+            """, nativeQuery = true)
+    int tryClaimRun(@Param("userId") Long userId,
+                    @Param("steamId") String steamId,
+                    @Param("runningStaleBefore") Instant runningStaleBefore);
+
+    @Modifying
+    @Query(value = """
+            UPDATE user_steam_sync
+               SET last_synced_at = :now,
+                   last_sync_status = :status
+             WHERE user_id = :userId
+            """, nativeQuery = true)
+    void markFinished(@Param("userId") Long userId,
+                      @Param("status") String status,
+                      @Param("now") Instant now);
+
+    @Modifying
+    @Query(value = "UPDATE user_steam_sync SET history_steam_id = :steamId WHERE user_id = :userId", nativeQuery = true)
+    void markHistoryBaseline(@Param("userId") Long userId, @Param("steamId") String steamId);
+
+    @Modifying
+    @Transactional
+    @Query(value = "UPDATE user_steam_sync SET user_seen_at = :now WHERE user_id = :userId", nativeQuery = true)
+    void touchUserSeen(@Param("userId") Long userId, @Param("now") Instant now);
+
+    List<UserSteamSync> findByUserSeenAtAfter(Instant since);
+}
+

src/main/java/core_service/modules/library/repo/WishlistGameRepository.java

@@ -0,0 +1,22 @@
+package core_service.modules.library.repo;
+
+import core_service.modules.library.domain.WishlistGame;
+import core_service.modules.library.domain.WishlistGameId;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.List;
+
+public interface WishlistGameRepository extends JpaRepository<WishlistGame, WishlistGameId> {
+
+    // Newest first; games without a date last.
+    @Query("select w from WishlistGame w where w.userId = :userId order by w.addedAt desc nulls last, w.appid")
+    List<WishlistGame> findForUser(@Param("userId") Long userId);
+
+    // flushAutomatically: the delete must reach the DB before the saveAll of the same appids.
+    @Modifying(flushAutomatically = true, clearAutomatically = true)
+    @Query("delete from WishlistGame w where w.userId = :userId")
+    void deleteByUserId(@Param("userId") Long userId);
+}

src/main/java/core_service/modules/library/service/BacklogService.java

@@ -0,0 +1,38 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.api.dto.BacklogEntryDto;
+import core_service.modules.library.domain.UserGame;
+import core_service.modules.library.domain.UserGameId;
+import core_service.modules.library.repo.UserGameRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Optional;
+
+@Service
+@RequiredArgsConstructor
+public class BacklogService {
+
+    private final UserGameRepository userGameRepository;
+
+    /**
+     * @return empty when the game is not in the user's active library
+     */
+    @Transactional
+    public Optional<BacklogEntryDto> update(Long userId, Long appid, BacklogEntryDto entry) {
+        return userGameRepository.findById(new UserGameId(userId, appid))
+                .filter(game -> game.getRemovedAt() == null)
+                .map(game -> {
+                    game.setStatus(entry.status());
+                    game.setRating(entry.rating());
+                    game.setNotes(entry.notes() == null || entry.notes().isBlank() ? null : entry.notes());
+                    game.setPriority(entry.priority());
+                    return toDto(game);
+                });
+    }
+
+    private static BacklogEntryDto toDto(UserGame game) {
+        return new BacklogEntryDto(game.getStatus(), game.getRating(), game.getNotes(), game.getPriority());
+    }
+}

src/main/java/core_service/modules/library/service/GameDetailService.java

@@ -0,0 +1,196 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.api.dto.AchievementDto;
+import core_service.modules.library.api.dto.GameDetailDto;
+import core_service.modules.library.domain.GameAchievementSchema;
+import core_service.modules.library.domain.GameAchievementSchemaMeta;
+import core_service.modules.library.domain.SteamGame;
+import core_service.modules.library.domain.UserGame;
+import core_service.modules.library.domain.UserGameAchievement;
+import core_service.modules.library.domain.UserGameAchievementMeta;
+import core_service.modules.library.domain.UserGameId;
+import core_service.modules.library.repo.GameAchievementSchemaMetaRepository;
+import core_service.modules.library.repo.GameTimeToBeatRepository;
+import core_service.modules.library.repo.GameAchievementSchemaRepository;
+import core_service.modules.library.repo.SteamGameRepository;
+import core_service.modules.library.repo.UserGameAchievementMetaRepository;
+import core_service.modules.library.repo.UserGameAchievementRepository;
+import core_service.modules.library.repo.UserGameRepository;
+import core_service.modules.steam_adapter.api.dto.response.SteamPlayerAchievementsResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamSchemaForGameResponse;
+import core_service.modules.steam_adapter.service.SteamApiService;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class GameDetailService {
+
+    private final UserGameRepository userGameRepository;
+    private final SteamGameRepository steamGameRepository;
+    private final GameAchievementSchemaRepository schemaRepository;
+    private final GameAchievementSchemaMetaRepository schemaMetaRepository;
+    private final UserGameAchievementRepository userAchievementRepository;
+    private final UserGameAchievementMetaRepository userAchievementMetaRepository;
+    private final SteamApiService steamApiService;
+    private final GameTimeToBeatRepository gameTimeToBeatRepository;
+
+    @Value("${app.library.achievement-ttl-hours:1}")
+    private long achievementTtlHours;
+
+    @Value("${app.library.schema-ttl-days:30}")
+    private long schemaTtlDays;
+
+    @Transactional
+    public Optional<GameDetailDto> getGameDetail(Long userId, String steamId, Long appid) {
+        Optional<UserGame> userGameOpt = userGameRepository.findById(new UserGameId(userId, appid));
+        if (userGameOpt.isEmpty() || userGameOpt.get().getRemovedAt() != null) {
+            return Optional.empty();
+        }
+        UserGame userGame = userGameOpt.get();
+        SteamGame meta = steamGameRepository.findById(appid).orElse(null);
+
+        refreshSchemaIfStale(appid);
+        boolean hasSchema = schemaMetaRepository.findById(appid).map(GameAchievementSchemaMeta::isHasSchema).orElse(false);
+
+        if (!hasSchema) {
+            return Optional.of(buildDto(userGame, meta, true, 0, 0, List.of()));
+        }
+
+        refreshUserAchievementsIfStale(userId, steamId, appid);
+
+        UserGameAchievementMeta userMeta = userAchievementMetaRepository.findByUserIdAndAppid(userId, appid).orElse(null);
+        boolean statsVisible = userMeta == null || userMeta.isStatsVisible();
+        int unlocked = userMeta != null ? userMeta.getAchievementsUnlocked() : 0;
+
+        List<GameAchievementSchema> schemaList = schemaRepository.findByAppid(appid);
+        Map<String, UserGameAchievement> userMap = new HashMap<>();
+        for (UserGameAchievement uga : userAchievementRepository.findByUserIdAndAppid(userId, appid)) {
+            userMap.put(uga.getApiName(), uga);
+        }
+
+        List<AchievementDto> achievementDtos = schemaList.stream()
+                .map(s -> {
+                    UserGameAchievement u = userMap.get(s.getApiName());
+                    boolean isUnlocked = u != null && u.isUnlocked();
+                    return new AchievementDto(
+                            s.getApiName(),
+                            s.getDisplayName(),
+                            s.getDescription(),
+                            s.getIconUrl(),
+                            s.getIconGrayUrl(),
+                            s.isHidden(),
+                            isUnlocked,
+                            u != null ? u.getUnlockedAt() : null
+                    );
+                })
+                .toList();
+
+        return Optional.of(buildDto(userGame, meta, statsVisible, schemaList.size(), unlocked, achievementDtos));
+    }
+
+    private GameDetailDto buildDto(UserGame userGame, SteamGame meta, boolean statsVisible,
+                                   int total, int unlocked, List<AchievementDto> achievements) {
+        boolean hasAchievements = total > 0;
+        int remaining = Math.max(0, total - unlocked);
+        double pct = total == 0 ? 0.0 : (unlocked * 100.0 / total);
+        return new GameDetailDto(
+                userGame.getAppid(),
+                meta != null ? meta.getName() : null,
+                meta != null ? meta.getImgIconUrl() : null,
+                userGame.getPlaytimeMinutes(),
+                userGame.getPlaytime2Weeks(),
+                userGame.getFirstSeenAt(),
+                userGame.getLastSeenAt(),
+                userGame.getStatus(),
+                userGame.getRating(),
+                userGame.getNotes(),
+                userGame.getPriority(),
+                hasAchievements,
+                statsVisible,
+                total,
+                unlocked,
+                remaining,
+                Math.round(pct * 10.0) / 10.0,
+                achievements,
+                gameTimeToBeatRepository.findById(userGame.getAppid())
+                        .map(t -> new GameDetailDto.TimeToBeatDto(t.getHastilyMinutes(), t.getNormallyMinutes(), t.getCompletelyMinutes()))
+                        .orElse(null)
+        );
+    }
+
+    private void refreshSchemaIfStale(Long appid) {
+        Optional<GameAchievementSchemaMeta> existing = schemaMetaRepository.findById(appid);
+        Instant now = Instant.now();
+        if (existing.isPresent() && existing.get().getRefreshedAt().isAfter(now.minus(Duration.ofDays(schemaTtlDays)))) {
+            return;
+        }
+        Optional<SteamSchemaForGameResponse.Game> schema = steamApiService.getSchemaForGame(appid);
+        boolean hasSchema = schema.isPresent()
+                && schema.get().availableGameStats() != null
+                && schema.get().availableGameStats().achievements() != null
+                && !schema.get().availableGameStats().achievements().isEmpty();
+
+        if (hasSchema) {
+            schemaRepository.deleteByAppid(appid);
+            List<GameAchievementSchema> rows = schema.get().availableGameStats().achievements().stream()
+                    .map(a -> new GameAchievementSchema(
+                            appid,
+                            a.name(),
+                            a.displayName(),
+                            a.description(),
+                            a.icon(),
+                            a.iconGray(),
+                            a.hidden() != null && a.hidden() == 1
+                    ))
+                    .toList();
+            schemaRepository.saveAll(rows);
+        }
+        int total = hasSchema ? schema.get().availableGameStats().achievements().size() : 0;
+        schemaMetaRepository.save(new GameAchievementSchemaMeta(appid, total, hasSchema, now));
+    }
+
+    private void refreshUserAchievementsIfStale(Long userId, String steamId, Long appid) {
+        Optional<UserGameAchievementMeta> existing = userAchievementMetaRepository.findByUserIdAndAppid(userId, appid);
+        Instant now = Instant.now();
+        if (existing.isPresent() && existing.get().getRefreshedAt().isAfter(now.minus(Duration.ofHours(achievementTtlHours)))) {
+            return;
+        }
+
+        Optional<SteamPlayerAchievementsResponse.PlayerStats> response = steamApiService.getPlayerAchievements(steamId, appid);
+        boolean visible = response.isPresent() && (response.get().success() == null || response.get().success());
+
+        if (!visible) {
+            userAchievementMetaRepository.save(new UserGameAchievementMeta(userId, appid, now, false, 0));
+            return;
+        }
+
+        List<SteamPlayerAchievementsResponse.Achievement> list = response.get().achievements();
+        userAchievementRepository.deleteByUserIdAndAppid(userId, appid);
+        int unlockedCount = 0;
+        if (list != null) {
+            List<UserGameAchievement> rows = list.stream()
+                    .map(a -> {
+                        boolean unlocked = a.achieved() != null && a.achieved() == 1;
+                        Instant unlockedAt = unlocked && a.unlockTime() != null && a.unlockTime() > 0
+                                ? Instant.ofEpochSecond(a.unlockTime()) : null;
+                        return new UserGameAchievement(userId, appid, a.apiName(), unlocked, unlockedAt);
+                    })
+                    .toList();
+            userAchievementRepository.saveAll(rows);
+            unlockedCount = (int) rows.stream().filter(UserGameAchievement::isUnlocked).count();
+        }
+        userAchievementMetaRepository.save(new UserGameAchievementMeta(userId, appid, now, true, unlockedCount));
+    }
+}

src/main/java/core_service/modules/library/service/LibraryQueryService.java

@@ -0,0 +1,173 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.api.dto.ActivityDto;
+import core_service.modules.library.api.dto.GameDto;
+import core_service.modules.library.api.dto.LibrarySummaryDto;
+import core_service.modules.library.api.dto.PublicLibraryDto;
+import core_service.modules.library.api.dto.RecentGameDto;
+import core_service.modules.library.api.dto.WishlistDto;
+import core_service.modules.library.domain.DayMinutes;
+import core_service.modules.library.domain.GameStatus;
+import core_service.modules.library.domain.GameTimeToBeat;
+import core_service.modules.library.domain.SteamGame;
+import core_service.modules.library.domain.UserGame;
+import core_service.modules.library.domain.UserSteamSync;
+import core_service.modules.library.repo.GameTimeToBeatRepository;
+import core_service.modules.library.repo.PlaytimeDayRepository;
+import core_service.modules.library.repo.SteamGameRepository;
+import core_service.modules.library.repo.UserGameRepository;
+import core_service.modules.library.repo.UserSteamSyncRepository;
+import core_service.modules.library.repo.WishlistGameRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.util.EnumMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+@Service
+@RequiredArgsConstructor
+@Transactional(readOnly = true)
+public class LibraryQueryService {
+
+    private static final int PUBLIC_PLAYING = 8;
+    private static final int PUBLIC_FINISHED = 12;
+
+    private final UserGameRepository userGameRepository;
+    private final UserSteamSyncRepository userSteamSyncRepository;
+    private final SteamGameRepository steamGameRepository;
+    private final PlaytimeDayRepository playtimeDayRepository;
+    private final WishlistGameRepository wishlistGameRepository;
+    private final GameTimeToBeatRepository gameTimeToBeatRepository;
+
+    @Value("${app.library.zone:Europe/Berlin}")
+    private ZoneId zone;
+
+    public long countOwnedGames(Long userId) {
+        return userGameRepository.countByUserIdAndRemovedAtIsNull(userId);
+    }
+
+    public Page<GameDto> listOwnedGames(Long userId, GameStatus status, String nameQuery, Integer maxMinutes,
+                                        Pageable pageable) {
+        Pageable stable = PageRequest.of(pageable.getPageNumber(), pageable.getPageSize(),
+                UserGameRepository.querySort(pageable.getSort()));
+        Page<UserGame> page = userGameRepository.findOwnedGames(
+                userId, status, UserGameRepository.containsPattern(nameQuery), maxMinutes, stable);
+        List<Long> appids = page.getContent().stream().map(UserGame::getAppid).toList();
+        Map<Long, SteamGame> meta = steamGameRepository.findAllById(appids).stream()
+                .collect(Collectors.toMap(SteamGame::getAppid, g -> g));
+        Map<Long, GameTimeToBeat> times = gameTimeToBeatRepository.findAllById(appids).stream()
+                .collect(Collectors.toMap(GameTimeToBeat::getAppid, t -> t));
+        return page.map(ug -> toDto(ug, meta.get(ug.getAppid()), times.get(ug.getAppid())));
+    }
+
+    /**
+     * @param excludeAppid the current suggestion, so a new pick differs from it; null for none
+     */
+    public LibrarySummaryDto getSummary(Long userId, Long excludeAppid) {
+        Map<GameStatus, Long> byStatus = countByStatus(userId);
+        long total = byStatus.values().stream().mapToLong(Long::longValue).sum();
+        long neverPlayed = userGameRepository.countByUserIdAndRemovedAtIsNullAndPlaytimeMinutes(userId, 0);
+        GameDto suggestion = userGameRepository.findRandomBacklogGame(userId, excludeAppid != null ? excludeAppid : -1)
+                .map(ug -> toDto(ug, steamGameRepository.findById(ug.getAppid()).orElse(null),
+                        gameTimeToBeatRepository.findById(ug.getAppid()).orElse(null)))
+                .orElse(null);
+        return new LibrarySummaryDto(total, byStatus, neverPlayed, suggestion, userGameRepository.sumBacklogMinutes(userId));
+    }
+
+    /**
+     * @param days the number of days up to and including today
+     */
+    public ActivityDto getActivity(Long userId, int days) {
+        LocalDate today = LocalDate.now(zone);
+        LocalDate from = today.minusDays(days - 1L);
+        Map<LocalDate, Long> played = playtimeDayRepository.minutesPerDay(userId, from).stream()
+                .collect(Collectors.toMap(DayMinutes::day, DayMinutes::minutes));
+        List<DayMinutes> perDay = from.datesUntil(today.plusDays(1))
+                .map(day -> new DayMinutes(day, played.getOrDefault(day, 0L)))
+                .toList();
+        long total = perDay.stream().mapToLong(DayMinutes::minutes).sum();
+
+        List<UserGame> recent = userGameRepository
+                .findTop5ByUserIdAndRemovedAtIsNullAndPlaytime2WeeksGreaterThanOrderByPlaytime2WeeksDesc(userId, 0);
+        Map<Long, SteamGame> meta = steamGameRepository.findAllById(recent.stream().map(UserGame::getAppid).toList())
+                .stream().collect(Collectors.toMap(SteamGame::getAppid, g -> g));
+        List<RecentGameDto> recentGames = recent.stream()
+                .map(ug -> new RecentGameDto(
+                        ug.getAppid(),
+                        meta.containsKey(ug.getAppid()) ? meta.get(ug.getAppid()).getName() : null,
+                        ug.getPlaytimeMinutes(),
+                        ug.getPlaytime2Weeks(),
+                        ug.getStatus()))
+                .toList();
+        return new ActivityDto(perDay, total, recentGames);
+    }
+
+    public PublicLibraryDto getPublicLibrary(Long userId) {
+        Map<GameStatus, Long> byStatus = countByStatus(userId);
+        List<UserGame> playing = userGameRepository.findByUserIdAndRemovedAtIsNullAndStatusIn(userId,
+                List.of(GameStatus.PLAYING),
+                PageRequest.of(0, PUBLIC_PLAYING, Sort.by(Sort.Direction.DESC, "playtimeMinutes").and(Sort.by("appid"))));
+        List<UserGame> finished = userGameRepository.findByUserIdAndRemovedAtIsNullAndStatusIn(userId,
+                List.of(GameStatus.FINISHED, GameStatus.COMPLETED),
+                PageRequest.of(0, PUBLIC_FINISHED, Sort.by(Sort.Order.desc("rating").nullsLast()).and(Sort.by("appid"))));
+        Map<Long, SteamGame> meta = steamGameRepository.findAllById(
+                        Stream.concat(playing.stream(), finished.stream()).map(UserGame::getAppid).toList())
+                .stream().collect(Collectors.toMap(SteamGame::getAppid, g -> g));
+        long total = byStatus.values().stream().mapToLong(Long::longValue).sum();
+        return new PublicLibraryDto(total, userGameRepository.sumPlaytime(userId), byStatus,
+                toPublicGames(playing, meta), toPublicGames(finished, meta));
+    }
+
+    // Every status, also those with 0 games.
+    private Map<GameStatus, Long> countByStatus(Long userId) {
+        Map<GameStatus, Long> byStatus = new EnumMap<>(GameStatus.class);
+        for (GameStatus status : GameStatus.values()) {
+            byStatus.put(status, 0L);
+        }
+        userGameRepository.countByStatus(userId).forEach(c -> byStatus.put(c.status(), c.count()));
+        return byStatus;
+    }
+
+    private static List<PublicLibraryDto.Game> toPublicGames(List<UserGame> games, Map<Long, SteamGame> meta) {
+        return games.stream()
+                .map(ug -> new PublicLibraryDto.Game(ug.getAppid(),
+                        meta.containsKey(ug.getAppid()) ? meta.get(ug.getAppid()).getName() : null,
+                        ug.getPlaytimeMinutes(), ug.getStatus(), ug.getRating()))
+                .toList();
+    }
+
+    public WishlistDto getWishlist(Long userId) {
+        return new WishlistDto(wishlistGameRepository.findForUser(userId).stream()
+                .map(w -> new WishlistDto.Game(w.getAppid(), w.getName(), w.getAddedAt(),
+                        w.getPrice(), w.getOriginalPrice(), w.getDiscountPct()))
+                .toList());
+    }
+
+    private static GameDto toDto(UserGame ug, SteamGame meta, GameTimeToBeat time) {
+        return new GameDto(
+                ug.getAppid(),
+                meta != null ? meta.getName() : null,
+                meta != null ? meta.getImgIconUrl() : null,
+                ug.getPlaytimeMinutes(),
+                ug.getStatus(),
+                ug.getRating(),
+                ug.getPriority(),
+                time != null ? time.getNormallyMinutes() : null);
+    }
+
+    public Optional<UserSteamSync> getSyncStatus(Long userId) {
+        return userSteamSyncRepository.findById(userId);
+    }
+}

src/main/java/core_service/modules/library/service/LibrarySyncService.java

@@ -0,0 +1,107 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.domain.UserSteamSync;
+import core_service.modules.library.repo.UserSteamSyncRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.List;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class LibrarySyncService {
+
+    private final UserSteamSyncRepository userSteamSyncRepository;
+    private final LibrarySyncWorker worker;
+
+    @Value("${app.library.sync-ttl-hours:24}")
+    private long syncTtlHours;
+
+    @Value("${app.library.force-sync-cooldown-seconds:60}")
+    private long forceSyncCooldownSeconds;
+
+    @Value("${app.library.running-stale-minutes:5}")
+    private long runningStaleMinutes;
+
+    @Value("${app.library.failed-retry-minutes:15}")
+    private long failedRetryMinutes;
+
+    @Value("${app.library.nightly-active-days:14}")
+    private long nightlyActiveDays;
+
+    /**
+     * Trigger sync only if data is older than TTL or was synced for another Steam ID.
+     * Cheap gate check on caller thread, actual sync runs async via worker.
+     */
+    public void syncIfStale(Long userId, String steamId) {
+        UserSteamSync sync = userSteamSyncRepository.findById(userId).orElse(null);
+        touchUserSeen(sync);
+        if (sync != null && isAlreadyRunning(sync)) {
+            log.debug("Sync already running for user {}", userId);
+            return;
+        }
+        if (sync != null && steamId.equals(sync.getSteamId()) && !isStale(sync)) {
+            return;
+        }
+        worker.runSync(userId, steamId);
+    }
+
+    /**
+     * Syncs every known Steam account shortly before midnight, so the playtime history gets the growth of each
+     * day even when the user does not open the app. Accounts are synced one after the other on the scheduler
+     * thread; accounts without a user request in the last {@code nightly-active-days} are skipped.
+     */
+    @Scheduled(cron = "${app.library.nightly-sync-cron:0 55 23 * * *}", zone = "${app.library.zone:Europe/Berlin}")
+    public void syncAllNightly() {
+        Instant activeSince = Instant.now().minus(Duration.ofDays(nightlyActiveDays));
+        List<UserSteamSync> accounts = userSteamSyncRepository.findByUserSeenAtAfter(activeSince);
+        log.info("Nightly sync for {} Steam accounts", accounts.size());
+        accounts.forEach(sync -> worker.runSyncNow(sync.getUserId(), sync.getSteamId()));
+    }
+
+    /**
+     * User-triggered sync. Throws SyncCooldownException if recently synced or running.
+     */
+    public void forceSync(Long userId, String steamId) {
+        UserSteamSync sync = userSteamSyncRepository.findById(userId).orElse(null);
+        touchUserSeen(sync);
+        if (sync != null && sync.getLastSyncedAt() != null) {
+            long sinceLast = Duration.between(sync.getLastSyncedAt(), Instant.now()).toSeconds();
+            if (sinceLast < forceSyncCooldownSeconds) {
+                throw new SyncCooldownException(forceSyncCooldownSeconds - sinceLast);
+            }
+        }
+        if (sync != null && isAlreadyRunning(sync)) {
+            throw new SyncCooldownException(forceSyncCooldownSeconds);
+        }
+        worker.runSync(userId, steamId);
+    }
+
+    // At most one write per user and hour; the nightly sync only needs to know "used recently".
+    private void touchUserSeen(UserSteamSync sync) {
+        Instant now = Instant.now();
+        if (sync != null && (sync.getUserSeenAt() == null || sync.getUserSeenAt().isBefore(now.minus(Duration.ofHours(1))))) {
+            userSteamSyncRepository.touchUserSeen(sync.getUserId(), now);
+        }
+    }
+
+    private boolean isStale(UserSteamSync sync) {
+        if (sync.getLastSyncedAt() == null) return true;
+        Duration maxAge = sync.getLastSyncStatus() == UserSteamSync.Status.FAILED
+                ? Duration.ofMinutes(failedRetryMinutes)
+                : Duration.ofHours(syncTtlHours);
+        return sync.getLastSyncedAt().isBefore(Instant.now().minus(maxAge));
+    }
+
+    private boolean isAlreadyRunning(UserSteamSync sync) {
+        if (sync.getLastSyncStatus() != UserSteamSync.Status.RUNNING) return false;
+        if (sync.getLastSyncedAt() == null) return true;
+        return sync.getLastSyncedAt().isAfter(Instant.now().minus(Duration.ofMinutes(runningStaleMinutes)));
+    }
+}

src/main/java/core_service/modules/library/service/LibrarySyncWorker.java

@@ -0,0 +1,196 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.domain.SteamGame;
+import core_service.modules.library.domain.UserGame;
+import core_service.modules.library.domain.UserGameId;
+import core_service.modules.library.domain.UserSteamSync;
+import core_service.modules.library.domain.WishlistGame;
+import core_service.modules.library.repo.PlaytimeDayRepository;
+import core_service.modules.library.repo.SteamGameRepository;
+import core_service.modules.library.repo.UserGameRepository;
+import core_service.modules.library.repo.UserSteamSyncRepository;
+import core_service.modules.library.repo.WishlistGameRepository;
+import core_service.modules.steam_adapter.api.dto.response.SteamOwnedGamesResponse;
+import core_service.modules.steam_adapter.service.SteamApiService;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneId;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import core_service.modules.library.domain.UserSteamSync.Status;
+
+/**
+ * Worker bean. Runs the actual Steam fetch + DB upserts.
+ * Separate bean so Spring proxy applies @Async and @Transactional
+ * (self-invocation from LibrarySyncService would bypass both).
+ */
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class LibrarySyncWorker {
+
+    private final SteamApiService steamApiService;
+    private final SteamGameRepository steamGameRepository;
+    private final UserGameRepository userGameRepository;
+    private final UserSteamSyncRepository userSteamSyncRepository;
+    private final PlaytimeDayRepository playtimeDayRepository;
+    private final WishlistGameRepository wishlistGameRepository;
+    private final TimeToBeatService timeToBeatService;
+
+    @Value("${app.library.running-stale-minutes:5}")
+    private long runningStaleMinutes;
+
+    @Value("${app.library.zone:Europe/Berlin}")
+    private ZoneId zone;
+
+    @Async
+    @Transactional
+    public void runSync(Long userId, String steamId) {
+        sync(userId, steamId);
+    }
+
+    /**
+     * Same as {@link #runSync}, but on the caller's thread. The nightly job uses it to sync one account after
+     * the other instead of starting all at once against the Steam rate limit and the connection pool.
+     */
+    @Transactional
+    public void runSyncNow(Long userId, String steamId) {
+        sync(userId, steamId);
+    }
+
+    private void sync(Long userId, String steamId) {
+        Instant runningStaleBefore = Instant.now().minus(Duration.ofMinutes(runningStaleMinutes));
+        UserSteamSync before = userSteamSyncRepository.findById(userId).orElse(null);
+        String previousSteamId = before != null ? before.getSteamId() : null;
+        String historySteamId = before != null ? before.getHistorySteamId() : null;
+        int claimed = userSteamSyncRepository.tryClaimRun(userId, steamId, runningStaleBefore);
+        if (claimed == 0) {
+            log.info("Sync skipped for user {} — another run already in flight", userId);
+            return;
+        }
+
+        Instant syncStartedAt = Instant.now();
+        Status finalStatus = Status.FAILED;
+        try {
+            boolean steamIdChanged = previousSteamId != null && !previousSteamId.equals(steamId);
+            // Growth needs a successful earlier sync of this account; else all its playtime would count as today.
+            boolean recordPlaytime = steamId.equals(historySteamId);
+            LocalDate today = LocalDate.ofInstant(syncStartedAt, zone);
+            if (steamIdChanged) {
+                // The old games belong to the previous Steam account. The upserts below restore the games this account also owns.
+                userGameRepository.softDeleteMissingSince(userId, syncStartedAt, Instant.now());
+                wishlistGameRepository.deleteByUserId(userId);
+            }
+            List<SteamOwnedGamesResponse.Game> games = steamApiService.getOwnedGames(steamId);
+            log.info("Sync user={} fetched {} games from Steam", userId, games.size());
+            // Before the empty check: an account without games can still have a public wishlist.
+            syncWishlist(userId, steamId, games);
+            if (games.isEmpty()) {
+                // Steam errors and a private "Game details" setting also end here. A soft-delete would wipe the library.
+                log.warn("Sync user={} got no games for SteamID {}", userId, steamId);
+                return;
+            }
+
+            for (SteamOwnedGamesResponse.Game g : games) {
+                if (g.appid() == null) continue;
+                upsertGame(g, syncStartedAt);
+                upsertUserGame(userId, g, syncStartedAt, recordPlaytime ? today : null);
+            }
+
+            int removed = userGameRepository.softDeleteMissingSince(userId, syncStartedAt, Instant.now());
+            if (removed > 0) {
+                log.info("Sync user={} soft-deleted {} games no longer owned", userId, removed);
+            }
+            userSteamSyncRepository.markHistoryBaseline(userId, steamId);
+            timeToBeatService.refresh(games.stream().filter(g -> g.appid() != null).map(g -> g.appid().longValue()).toList());
+            finalStatus = Status.OK;
+        } catch (Exception e) {
+            log.error("Sync failed for user {}", userId, e);
+        } finally {
+            userSteamSyncRepository.markFinished(userId, finalStatus.name(), Instant.now());
+        }
+    }
+
+    private void syncWishlist(Long userId, String steamId, List<SteamOwnedGamesResponse.Game> ownedGames) {
+        Optional<List<SteamApiService.WishlistItem>> wishlist = steamApiService.getWishlist(steamId);
+        if (wishlist.isEmpty()) {
+            log.warn("Sync user={} kept the old wishlist, Steam did not answer", userId);
+            return;
+        }
+        Set<Long> owned = ownedGames.stream()
+                .filter(g -> g.appid() != null)
+                .map(g -> g.appid().longValue())
+                .collect(Collectors.toSet());
+        List<SteamApiService.WishlistItem> wanted = wishlist.get().stream()
+                .filter(item -> !owned.contains(item.appid()))
+                .toList();
+        Map<Long, SteamApiService.StoreItem> store = wanted.isEmpty()
+                ? Map.of()
+                : steamApiService.getStoreItems(wanted.stream().map(SteamApiService.WishlistItem::appid).toList());
+        // A failed store batch leaves apps out of `store`; they keep the name and price of the last sync.
+        Map<Long, WishlistGame> previous = wishlistGameRepository.findForUser(userId).stream()
+                .collect(Collectors.toMap(WishlistGame::getAppid, w -> w));
+        wishlistGameRepository.deleteByUserId(userId);
+        wishlistGameRepository.saveAll(wanted.stream().map(item -> {
+            SteamApiService.StoreItem info = store.get(item.appid());
+            if (info != null) {
+                return new WishlistGame(userId, item.appid(), info.name(), item.addedAt(),
+                        info.price(), info.originalPrice(), info.discountPct());
+            }
+            WishlistGame old = previous.get(item.appid());
+            return old == null
+                    ? new WishlistGame(userId, item.appid(), null, item.addedAt(), null, null, 0)
+                    : new WishlistGame(userId, item.appid(), old.getName(), item.addedAt(),
+                    old.getPrice(), old.getOriginalPrice(), old.getDiscountPct());
+        }).toList());
+    }
+
+    private void upsertGame(SteamOwnedGamesResponse.Game g, Instant now) {
+        Long appid = g.appid().longValue();
+        SteamGame existing = steamGameRepository.findById(appid).orElse(null);
+        if (existing == null) {
+            steamGameRepository.save(new SteamGame(appid, g.name(), g.imgIconUrl(), now));
+        } else {
+            existing.setName(g.name());
+            existing.setImgIconUrl(g.imgIconUrl());
+            existing.setLastSeenAt(now);
+        }
+    }
+
+    /**
+     * @param playedOn the day that gets the playtime growth, null to record none
+     */
+    private void upsertUserGame(Long userId, SteamOwnedGamesResponse.Game g, Instant now, LocalDate playedOn) {
+        Long appid = g.appid().longValue();
+        UserGame existing = userGameRepository.findById(new UserGameId(userId, appid)).orElse(null);
+        int playtime = g.playtimeForever() != null ? g.playtimeForever() : 0;
+        int previousPlaytime = existing != null ? existing.getPlaytimeMinutes() : 0;
+        int playtime2Weeks = g.playtime2Weeks() != null ? g.playtime2Weeks() : 0;
+        if (existing == null) {
+            UserGame created = new UserGame(userId, appid, playtime, now, now);
+            created.setPlaytime2Weeks(playtime2Weeks);
+            userGameRepository.save(created);
+        } else {
+            existing.setPlaytimeMinutes(playtime);
+            existing.setPlaytime2Weeks(playtime2Weeks);
+            existing.setLastSeenAt(now);
+            existing.setRemovedAt(null);
+        }
+        // A Steam recount can lower playtime_forever; the growth back to the old value counts again. Accepted.
+        if (playedOn != null && playtime > previousPlaytime) {
+            playtimeDayRepository.addMinutes(userId, appid, playedOn, playtime - previousPlaytime);
+        }
+    }
+}

src/main/java/core_service/modules/library/service/SteamProfileService.java

@@ -0,0 +1,24 @@
+package core_service.modules.library.service;
+
+import core_service.modules.library.api.dto.SteamProfileDto;
+import core_service.modules.steam_adapter.service.SteamApiService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.stereotype.Service;
+
+@Service
+@RequiredArgsConstructor
+public class SteamProfileService {
+
+    private static final SteamProfileDto NONE = new SteamProfileDto(null, null);
+
+    private final SteamApiService steamApiService;
+
+    public SteamProfileDto getProfile(Long steamId) {
+        if (steamId == null) return NONE;
+        return steamApiService.getPlayerSummary(String.valueOf(steamId))
+                // The frontend puts the avatar into an img src, so only an https URL passes.
+                .map(player -> new SteamProfileDto(player.personaname(),
+                        player.avatarfull() != null && player.avatarfull().startsWith("https://") ? player.avatarfull() : null))
+                .orElse(NONE);
+    }
+}

src/main/java/core_service/modules/library/service/SyncCooldownException.java

@@ -0,0 +1,14 @@
+package core_service.modules.library.service;
+
+public class SyncCooldownException extends RuntimeException {
+    private final long retryAfterSeconds;
+
+    public SyncCooldownException(long retryAfterSeconds) {
+        super("Sync on cooldown, retry in " + retryAfterSeconds + "s");
+        this.retryAfterSeconds = retryAfterSeconds;
+    }
+
+    public long getRetryAfterSeconds() {
+        return retryAfterSeconds;
+    }
+}

src/main/java/core_service/modules/library/service/TimeToBeatService.java

@@ -0,0 +1,55 @@
+package core_service.modules.library.service;
+
+import core_service.modules.igdb_adapter.service.IgdbApiService;
+import core_service.modules.library.repo.GameTimeToBeatRepository;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Service;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.util.Collection;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.TreeSet;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class TimeToBeatService {
+
+    private final IgdbApiService igdbApiService;
+    private final GameTimeToBeatRepository gameTimeToBeatRepository;
+
+    @Value("${app.library.time-to-beat-ttl-days:30}")
+    private long ttlDays;
+
+    /**
+     * Asks IGDB for the apps without a fresh row and stores the answer, also "no data". Does nothing when IGDB is
+     * off, and stores nothing when IGDB fails, so the apps are asked again on the next sync.
+     */
+    public void refresh(Collection<Long> appids) {
+        if (!igdbApiService.isEnabled() || appids.isEmpty()) return;
+        // Sorted: parallel syncs then lock the upserted rows in the same order and cannot deadlock.
+        Set<Long> stale = new TreeSet<>(appids);
+        stale.removeAll(gameTimeToBeatRepository.findFreshAppids(appids, Instant.now().minus(Duration.ofDays(ttlDays))));
+        if (stale.isEmpty()) return;
+
+        Optional<Map<Long, IgdbApiService.TimeToBeat>> answer = igdbApiService.getTimeToBeat(stale);
+        if (answer.isEmpty()) {
+            log.warn("Time to beat for {} apps not refreshed, IGDB did not answer", stale.size());
+            return;
+        }
+        Instant now = Instant.now();
+        for (Long appid : stale) {
+            IgdbApiService.TimeToBeat time = answer.get().get(appid);
+            if (time == null) {
+                gameTimeToBeatRepository.upsert(appid, null, null, null, now);
+            } else {
+                gameTimeToBeatRepository.upsert(appid, time.hastilyMinutes(), time.normallyMinutes(), time.completelyMinutes(), now);
+            }
+        }
+    }
+}

src/main/java/core_service/modules/stats/api/PublicStatsController.java

@@ -0,0 +1,22 @@
+package core_service.modules.stats.api;
+
+import core_service.modules.stats.api.dto.PublicStatsDto;
+import core_service.modules.stats.service.PublicStatsService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/api/stats")
+@RequiredArgsConstructor
+public class PublicStatsController {
+
+    private final PublicStatsService publicStatsService;
+
+    @GetMapping("/public")
+    public ResponseEntity<PublicStatsDto> getPublicStats() {
+        return ResponseEntity.ok(publicStatsService.getPublicStats());
+    }
+}

src/main/java/core_service/modules/stats/api/dto/PublicStatsDto.java

@@ -0,0 +1,19 @@
+package core_service.modules.stats.api.dto;
+
+import java.util.List;
+
+public record PublicStatsDto(
+        long totalDistinctGames,
+        long totalLibraryEntries,
+        long totalGamesPlayed,
+        long totalPlaytimeMinutes,
+        long totalPlaytimeDays,
+        long totalUsersWithLibrary,
+        long avgGamesPerUser,
+        long biggestLibrary,
+        long biggestBacklog,
+        List<TopGame> topOwnedGames,
+        List<TopGame> topPlayedGames
+) {
+    public record TopGame(Long appid, String name, String imgIconUrl, long value) {}
+}

src/main/java/core_service/modules/stats/repo/StatsRepository.java

@@ -0,0 +1,93 @@
+package core_service.modules.stats.repo;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Map;
+
+@Repository
+public class StatsRepository {
+
+    private final JdbcTemplate jdbc;
+
+    @Autowired
+    public StatsRepository(JdbcTemplate jdbc) {
+        this.jdbc = jdbc;
+    }
+
+    public long countDistinctGames() {
+        Long v = jdbc.queryForObject(
+                "SELECT COUNT(DISTINCT appid) FROM user_game WHERE removed_at IS NULL", Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long countLibraryEntries() {
+        Long v = jdbc.queryForObject(
+                "SELECT COUNT(*) FROM user_game WHERE removed_at IS NULL", Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long countGamesPlayed() {
+        Long v = jdbc.queryForObject(
+                "SELECT COUNT(*) FROM user_game WHERE removed_at IS NULL AND playtime_minutes > 0", Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long sumPlaytimeMinutes() {
+        Long v = jdbc.queryForObject(
+                "SELECT COALESCE(SUM(playtime_minutes), 0) FROM user_game WHERE removed_at IS NULL", Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long countUsersWithLibrary() {
+        Long v = jdbc.queryForObject(
+                "SELECT COUNT(DISTINCT user_id) FROM user_game WHERE removed_at IS NULL", Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long biggestLibrary() {
+        Long v = jdbc.queryForObject("""
+                SELECT COALESCE(MAX(c), 0) FROM (
+                    SELECT COUNT(*) AS c FROM user_game
+                    WHERE removed_at IS NULL GROUP BY user_id
+                ) t
+                """, Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public long biggestBacklog() {
+        Long v = jdbc.queryForObject("""
+                SELECT COALESCE(MAX(c), 0) FROM (
+                    SELECT COUNT(*) AS c FROM user_game
+                    WHERE removed_at IS NULL AND playtime_minutes = 0 GROUP BY user_id
+                ) t
+                """, Long.class);
+        return v != null ? v : 0L;
+    }
+
+    public List<Map<String, Object>> topOwnedGames(int limit) {
+        return jdbc.queryForList("""
+                SELECT ug.appid, sg.name, sg.img_icon_url, COUNT(*) AS value
+                FROM user_game ug
+                LEFT JOIN steam_game sg ON sg.appid = ug.appid
+                WHERE ug.removed_at IS NULL
+                GROUP BY ug.appid, sg.name, sg.img_icon_url
+                ORDER BY value DESC
+                LIMIT ?
+                """, limit);
+    }
+
+    public List<Map<String, Object>> topPlayedGames(int limit) {
+        return jdbc.queryForList("""
+                SELECT ug.appid, sg.name, sg.img_icon_url, SUM(ug.playtime_minutes) AS value
+                FROM user_game ug
+                LEFT JOIN steam_game sg ON sg.appid = ug.appid
+                WHERE ug.removed_at IS NULL
+                GROUP BY ug.appid, sg.name, sg.img_icon_url
+                ORDER BY value DESC
+                LIMIT ?
+                """, limit);
+    }
+}

src/main/java/core_service/modules/stats/service/PublicStatsService.java

@@ -0,0 +1,60 @@
+package core_service.modules.stats.service;
+
+import core_service.modules.stats.api.dto.PublicStatsDto;
+import core_service.modules.stats.repo.StatsRepository;
+import lombok.RequiredArgsConstructor;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+import java.util.Map;
+
+@Service
+@RequiredArgsConstructor
+public class PublicStatsService {
+
+    private static final int TOP_LIMIT = 5;
+
+    private final StatsRepository statsRepository;
+
+    @Cacheable(value = "publicStats", key = "'global'")
+    public PublicStatsDto getPublicStats() {
+        long distinctGames = statsRepository.countDistinctGames();
+        long libraryEntries = statsRepository.countLibraryEntries();
+        long gamesPlayed = statsRepository.countGamesPlayed();
+        long playtimeMinutes = statsRepository.sumPlaytimeMinutes();
+        long usersWithLibrary = statsRepository.countUsersWithLibrary();
+        long biggestLibrary = statsRepository.biggestLibrary();
+        long biggestBacklog = statsRepository.biggestBacklog();
+        long avgGames = usersWithLibrary == 0 ? 0L : libraryEntries / usersWithLibrary;
+        long playtimeDays = playtimeMinutes / (60 * 24);
+
+        List<PublicStatsDto.TopGame> topOwned = mapTop(statsRepository.topOwnedGames(TOP_LIMIT));
+        List<PublicStatsDto.TopGame> topPlayed = mapTop(statsRepository.topPlayedGames(TOP_LIMIT));
+
+        return new PublicStatsDto(
+                distinctGames,
+                libraryEntries,
+                gamesPlayed,
+                playtimeMinutes,
+                playtimeDays,
+                usersWithLibrary,
+                avgGames,
+                biggestLibrary,
+                biggestBacklog,
+                topOwned,
+                topPlayed
+        );
+    }
+
+    private List<PublicStatsDto.TopGame> mapTop(List<Map<String, Object>> rows) {
+        return rows.stream()
+                .map(r -> new PublicStatsDto.TopGame(
+                        ((Number) r.get("appid")).longValue(),
+                        (String) r.get("name"),
+                        (String) r.get("img_icon_url"),
+                        ((Number) r.get("value")).longValue()
+                ))
+                .toList();
+    }
+}

src/main/java/core_service/modules/steam_adapter/api/SteamController.java

@@ -0,0 +1,30 @@
+package core_service.modules.steam_adapter.api;
+
+import core_service.modules.steam_adapter.service.SteamApiService;
+import core_service.shared.security.UserPrincipal;
+import lombok.RequiredArgsConstructor;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.annotation.AuthenticationPrincipal;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Map;
+
+@RestController
+@RequestMapping("/api/steam")
+@RequiredArgsConstructor
+public class SteamController {
+
+    private final SteamApiService steamApiService;
+
+    @GetMapping("/games-count")
+    public ResponseEntity<?> getGamesCount(@AuthenticationPrincipal UserPrincipal principal) {
+        if (principal.steamId() == null) {
+            return ResponseEntity.ok(Map.of("count", 0, "hasSteamId", false));
+        }
+
+        int count = steamApiService.getOwnedGamesCount(String.valueOf(principal.steamId()));
+        return ResponseEntity.ok(Map.of("count", count, "hasSteamId", true));
+    }
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamOwnedGamesResponse.java

@@ -0,0 +1,27 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import java.util.List;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record SteamOwnedGamesResponse(
+        @JsonProperty("response") OwnedGamesResponse response
+) {
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record OwnedGamesResponse(
+            @JsonProperty("game_count") Integer gameCount,
+            @JsonProperty("games") List<Game> games
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Game(
+            @JsonProperty("appid") Integer appid,
+            @JsonProperty("name") String name,
+            @JsonProperty("playtime_forever") Integer playtimeForever,
+            @JsonProperty("img_icon_url") String imgIconUrl,
+            @JsonProperty("has_community_visible_stats") Boolean hasCommunityVisibleStats,
+            @JsonProperty("playtime_2weeks") Integer playtime2Weeks
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamPlayerAchievementsResponse.java

@@ -0,0 +1,28 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record SteamPlayerAchievementsResponse(
+        @JsonProperty("playerstats") PlayerStats playerstats
+) {
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record PlayerStats(
+            @JsonProperty("steamID") String steamId,
+            @JsonProperty("gameName") String gameName,
+            @JsonProperty("achievements") List<Achievement> achievements,
+            @JsonProperty("success") Boolean success,
+            @JsonProperty("error") String error
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Achievement(
+            @JsonProperty("apiname") String apiName,
+            @JsonProperty("achieved") Integer achieved,
+            @JsonProperty("unlocktime") Long unlockTime
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamPlayerSummaryResponse.java

@@ -0,0 +1,15 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import java.util.List;
+
+public record SteamPlayerSummaryResponse(SteamResponse response) {
+
+    public record SteamResponse(List<Player> players) {}
+
+    public record Player(
+            String steamid,
+            String personaname,
+            String profileurl,
+            String avatarfull
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamProfileAndGamesResponse.java

@@ -0,0 +1,9 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import java.util.List;
+
+public record SteamProfileAndGamesResponse(
+        SteamPlayerSummaryResponse.Player player,
+        List<SteamOwnedGamesResponse.Game> games
+) {
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamSchemaForGameResponse.java

@@ -0,0 +1,34 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record SteamSchemaForGameResponse(
+        @JsonProperty("game") Game game
+) {
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Game(
+            @JsonProperty("gameName") String gameName,
+            @JsonProperty("gameVersion") String gameVersion,
+            @JsonProperty("availableGameStats") AvailableGameStats availableGameStats
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record AvailableGameStats(
+            @JsonProperty("achievements") List<Achievement> achievements
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Achievement(
+            @JsonProperty("name") String name,
+            @JsonProperty("displayName") String displayName,
+            @JsonProperty("description") String description,
+            @JsonProperty("hidden") Integer hidden,
+            @JsonProperty("icon") String icon,
+            @JsonProperty("icongray") String iconGray
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamStoreItemsResponse.java

@@ -0,0 +1,36 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record SteamStoreItemsResponse(
+        @JsonProperty("response") StoreItemsResponse response
+) {
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record StoreItemsResponse(
+            @JsonProperty("store_items") List<StoreItem> storeItems
+    ) {}
+
+    /**
+     * @param success 1 for a known app
+     * @param bestPurchaseOption null for an app without a price, e.g. not released yet
+     */
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record StoreItem(
+            @JsonProperty("appid") Long appid,
+            @JsonProperty("success") Integer success,
+            @JsonProperty("name") String name,
+            @JsonProperty("best_purchase_option") PurchaseOption bestPurchaseOption
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record PurchaseOption(
+            @JsonProperty("formatted_final_price") String formattedFinalPrice,
+            @JsonProperty("formatted_original_price") String formattedOriginalPrice,
+            @JsonProperty("discount_pct") Integer discountPct
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/api/dto/response/SteamWishlistResponse.java

@@ -0,0 +1,26 @@
+package core_service.modules.steam_adapter.api.dto.response;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.List;
+
+@JsonIgnoreProperties(ignoreUnknown = true)
+public record SteamWishlistResponse(
+        @JsonProperty("response") WishlistResponse response
+) {
+
+    /**
+     * @param items null for an empty or private wishlist
+     */
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record WishlistResponse(
+            @JsonProperty("items") List<Item> items
+    ) {}
+
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public record Item(
+            @JsonProperty("appid") Long appid,
+            @JsonProperty("date_added") Long dateAdded
+    ) {}
+}

src/main/java/core_service/modules/steam_adapter/config/SteamClientConfig.java

@@ -0,0 +1,16 @@
+package core_service.modules.steam_adapter.config;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.client.RestClient;
+
+@Configuration
+public class SteamClientConfig {
+    @Bean
+    public RestClient steamRestClient(@Value("${app.steam.base-url}") String baseUrl) {
+        return RestClient.builder()
+                .baseUrl(baseUrl)
+                .build();
+    }
+}

src/main/java/core_service/modules/steam_adapter/service/SteamApiService.java

@@ -0,0 +1,300 @@
+package core_service.modules.steam_adapter.service;
+
+import core_service.modules.steam_adapter.api.dto.response.SteamOwnedGamesResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamPlayerAchievementsResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamPlayerSummaryResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamProfileAndGamesResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamSchemaForGameResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamStoreItemsResponse;
+import core_service.modules.steam_adapter.api.dto.response.SteamWishlistResponse;
+import org.springframework.web.client.HttpClientErrorException;
+import io.github.resilience4j.ratelimiter.annotation.RateLimiter;
+import io.github.resilience4j.retry.annotation.Retry;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.RestClient;
+
+import java.time.Instant;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class SteamApiService {
+
+    private final RestClient steamRestClient;
+
+    private static final int STORE_ITEMS_BATCH = 100;
+
+    @Value("${app.steam.api-key}")
+    private String apiKey;
+
+    @Value("${app.steam.store-language:german}")
+    private String storeLanguage;
+
+    @Value("${app.steam.store-country:DE}")
+    private String storeCountry;
+
+    @Cacheable(value = "steamGameCount", key = "#steamId")
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public int getOwnedGamesCount(String steamId) {
+        if (apiKey == null || apiKey.isEmpty() || apiKey.equals("${STEAM_API_KEY}")) {
+            log.error("Steam API Key is not configured correctly!");
+            return 0;
+        }
+
+        try {
+            log.info("Fetching owned games count for SteamID: {} using API Key starting with: {}", 
+                steamId, apiKey.substring(0, Math.min(apiKey.length(), 4)));
+
+            SteamOwnedGamesResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/IPlayerService/GetOwnedGames/v1/")
+                            .queryParam("key", apiKey)
+                            .queryParam("steamid", steamId)
+                            .queryParam("include_appinfo", "true")
+                            .queryParam("include_played_free_games", "true")
+                            .queryParam("format", "json")
+                            .build())
+                    .retrieve()
+                    .body(SteamOwnedGamesResponse.class);
+
+            log.info("Steam API Response object for {}: {}", steamId, response);
+
+            if (response != null && response.response() != null) {
+                Integer count = response.response().gameCount();
+                if (count == null) {
+                    if (response.response().games() != null) {
+                        int size = response.response().games().size();
+                        log.info("game_count was null, but games list has {} entries for SteamID: {}", size, steamId);
+                        return size;
+                    }
+                    log.warn("Steam API returned an empty response object for SteamID: {}. Check if the ID is correct and 'Game details' are Public.", steamId);
+                    return 0;
+                }
+                log.info("Successfully fetched {} games for SteamID: {}", count, steamId);
+                return count;
+            }
+
+        } catch (Exception e) {
+            log.error("Error communicating with Steam API for game count of SteamID: {}", steamId, e);
+        }
+
+        return 0;
+    }
+
+    public Optional<SteamProfileAndGamesResponse> getFullPlayerProfile(String steamId) {
+        var playerOpt = getPlayerSummary(steamId);
+        if (playerOpt.isEmpty()) {
+            return Optional.empty();
+        }
+
+        var games = getOwnedGames(steamId);
+        return Optional.of(new SteamProfileAndGamesResponse(playerOpt.get(), games));
+    }
+
+    // Asked on every page load for the avatar in the header.
+    @Cacheable(value = "steamPlayerSummary", key = "#steamId", unless = "#result == null")
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public Optional<SteamPlayerSummaryResponse.Player> getPlayerSummary(String steamId) {
+        try {
+            log.info("Fetching Steam profile for SteamID: {}", steamId);
+
+            SteamPlayerSummaryResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/ISteamUser/GetPlayerSummaries/v0002/")
+                            .queryParam("key", apiKey)
+                            .queryParam("steamids", steamId)
+                            .build())
+                    .retrieve()
+                    .body(SteamPlayerSummaryResponse.class);
+
+            if (response != null && response.response() != null && !response.response().players().isEmpty()) {
+                return Optional.of(response.response().players().getFirst());
+            }
+
+        } catch (Exception e) {
+            log.error("Error communicating with Steam API for SteamID: {}", steamId, e);
+        }
+
+        return Optional.empty();
+    }
+
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public List<SteamOwnedGamesResponse.Game> getOwnedGames(String steamId) {
+        try {
+            log.info("Fetching owned games for SteamID: {}", steamId);
+
+            SteamOwnedGamesResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/IPlayerService/GetOwnedGames/v1/")
+                            .queryParam("key", apiKey)
+                            .queryParam("steamid", steamId)
+                            .queryParam("include_appinfo", 1)
+                            .queryParam("include_played_free_games", 1)
+                            .build())
+                    .retrieve()
+                    .body(SteamOwnedGamesResponse.class);
+
+            if (response != null && response.response() != null && response.response().games() != null) {
+                return response.response().games();
+            }
+
+        } catch (Exception e) {
+            log.error("Error communicating with Steam API for games of SteamID: {}", steamId, e);
+        }
+
+        return Collections.emptyList();
+    }
+
+    public record WishlistItem(long appid, Instant addedAt) {}
+
+    /**
+     * @param discountPct 0 when not on sale
+     */
+    public record StoreItem(String name, String price, String originalPrice, int discountPct) {}
+
+    /**
+     * Needs a public wishlist; a private one comes back as an empty list, like an empty one.
+     *
+     * @return empty on a Steam error, so the caller can keep the list it has
+     */
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public Optional<List<WishlistItem>> getWishlist(String steamId) {
+        try {
+            SteamWishlistResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/IWishlistService/GetWishlist/v1/")
+                            .queryParam("key", apiKey)
+                            .queryParam("steamid", steamId)
+                            .build())
+                    .retrieve()
+                    .body(SteamWishlistResponse.class);
+            if (response == null || response.response() == null || response.response().items() == null) {
+                return Optional.of(List.of());
+            }
+            return Optional.of(response.response().items().stream()
+                    .filter(item -> item.appid() != null)
+                    .map(item -> new WishlistItem(item.appid(),
+                            item.dateAdded() != null ? Instant.ofEpochSecond(item.dateAdded()) : null))
+                    .toList());
+        } catch (Exception e) {
+            log.error("Error communicating with Steam API for the wishlist of SteamID: {}", steamId, e);
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Store name and current price per app, asked in batches of {@value #STORE_ITEMS_BATCH}. Apps Steam does not
+     * know, and batches that fail, are missing from the result. One rate-limit permit covers all batches; a
+     * wishlist rarely has more than one.
+     */
+    @RateLimiter(name = "steamApi")
+    public Map<Long, StoreItem> getStoreItems(List<Long> appids) {
+        Map<Long, StoreItem> result = new HashMap<>();
+        for (int from = 0; from < appids.size(); from += STORE_ITEMS_BATCH) {
+            result.putAll(getStoreItemsBatch(appids.subList(from, Math.min(from + STORE_ITEMS_BATCH, appids.size()))));
+        }
+        return result;
+    }
+
+    private Map<Long, StoreItem> getStoreItemsBatch(List<Long> appids) {
+        String ids = appids.stream().map(id -> "{\"appid\":" + id + "}").collect(Collectors.joining(","));
+        String inputJson = "{\"ids\":[" + ids + "],\"context\":{\"language\":\"" + storeLanguage
+                + "\",\"country_code\":\"" + storeCountry + "\"},\"data_request\":{}}";
+        try {
+            SteamStoreItemsResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/IStoreBrowseService/GetItems/v1/")
+                            .queryParam("key", apiKey)
+                            .queryParam("input_json", "{inputJson}")
+                            .build(inputJson))
+                    .retrieve()
+                    .body(SteamStoreItemsResponse.class);
+            if (response == null || response.response() == null || response.response().storeItems() == null) {
+                return Map.of();
+            }
+            Map<Long, StoreItem> items = new HashMap<>();
+            for (SteamStoreItemsResponse.StoreItem item : response.response().storeItems()) {
+                if (item.appid() == null || !Integer.valueOf(1).equals(item.success())) continue;
+                SteamStoreItemsResponse.PurchaseOption price = item.bestPurchaseOption();
+                items.put(item.appid(), new StoreItem(
+                        item.name(),
+                        price != null ? price.formattedFinalPrice() : null,
+                        price != null ? price.formattedOriginalPrice() : null,
+                        price != null && price.discountPct() != null ? price.discountPct() : 0));
+            }
+            return items;
+        } catch (Exception e) {
+            log.error("Error communicating with Steam API for store items {}", appids, e);
+            return Map.of();
+        }
+    }
+
+    /**
+     * Per-game achievement schema (global, language-aware).
+     * Returns empty when game has no achievements or Steam returns no schema.
+     */
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public Optional<SteamSchemaForGameResponse.Game> getSchemaForGame(long appid) {
+        try {
+            SteamSchemaForGameResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/ISteamUserStats/GetSchemaForGame/v2/")
+                            .queryParam("key", apiKey)
+                            .queryParam("appid", appid)
+                            .build())
+                    .retrieve()
+                    .body(SteamSchemaForGameResponse.class);
+
+            if (response != null && response.game() != null) {
+                return Optional.of(response.game());
+            }
+        } catch (Exception e) {
+            log.warn("GetSchemaForGame failed for appid {}: {}", appid, e.getMessage());
+        }
+        return Optional.empty();
+    }
+
+    /**
+     * Per-user achievement state for a single game.
+     * Returns empty when profile/stats are private (HTTP 403) or game has no achievements.
+     */
+    @RateLimiter(name = "steamApi")
+    @Retry(name = "steamApi")
+    public Optional<SteamPlayerAchievementsResponse.PlayerStats> getPlayerAchievements(String steamId, long appid) {
+        try {
+            SteamPlayerAchievementsResponse response = steamRestClient.get()
+                    .uri(uriBuilder -> uriBuilder
+                            .path("/ISteamUserStats/GetPlayerAchievements/v1/")
+                            .queryParam("key", apiKey)
+                            .queryParam("steamid", steamId)
+                            .queryParam("appid", appid)
+                            .build())
+                    .retrieve()
+                    .body(SteamPlayerAchievementsResponse.class);
+
+            if (response != null && response.playerstats() != null) {
+                return Optional.of(response.playerstats());
+            }
+        } catch (HttpClientErrorException.Forbidden e) {
+            log.info("Achievements hidden by Steam privacy for steamId={} appid={}", steamId, appid);
+        } catch (Exception e) {
+            log.warn("GetPlayerAchievements failed for steamId={} appid={}: {}", steamId, appid, e.getMessage());
+        }
+        return Optional.empty();
+    }
+}

src/main/java/core_service/shared/security/ProfileTicketVerifier.java

@@ -0,0 +1,14 @@
+package core_service.shared.security;
+
+import java.util.Optional;
+
+/**
+ * Port for the public-profile ticket that Auth issues for a user with a public profile.
+ */
+public interface ProfileTicketVerifier {
+
+    /**
+     * @return the user of a valid, unexpired ticket; empty for anything else, also for a login token
+     */
+    Optional<Long> verifyProfileTicket(String ticket);
+}

src/main/java/core_service/shared/security/UserPrincipal.java

@@ -4,7 +4,8 @@ import java.security.Principal;
 
 public record UserPrincipal(
         String id,
-        String email
+        String email,
+        Long steamId
 ) implements Principal {
 
     @Override
@@ -16,3 +17,4 @@ public record UserPrincipal(
         return Long.parseLong(id);
     }
 }
+

src/main/resources/application.yml

@@ -3,35 +3,79 @@ spring:
     name: tbp-core-service
   profiles:
     active: prod
-  datasource:
-    url: jdbc:postgresql://${DB_HOST}:5432/tbp_core
-    username: ${DB_USER}
-    password: ${DB_PASS}
+  jackson:
+    deserialization:
+      accept-float-as-int: false
   jpa:
     open-in-view: true
-    hibernate:
-      ddl-auto: validate
   flyway:
     enabled: true
     baseline-on-migrate: true
     locations: classpath:db/migration
+  threads:
+    virtual:
+      enabled: true
+  mvc:
+    apiversion:
+      use:
+        query-parameter: version
+      default: "1.0"
+      supported: 1.0, 2,0
 
 server:
-  port: 8081
+  port: 8090
 
 management:
   endpoints:
     web:
       exposure:
-        include: health, prometheus, metrics
-
+        include: health
+  endpoint:
+    health:
+      show-details: never
 security:
   jwt:
-    secret: ${JWT_SECRET}
-
+    public-key: ${JWT_PUBLIC_KEY}
 app:
   cors:
     allowed-origins: "https://tbp.andreas-dahm.eu"
+  steam:
+    api-key: ${STEAM_API_KEY}
+    base-url: https://api.steampowered.com
+    imageService-url: https://cdn.cloudflare.steamstatic.com/steam/apps/
+  igdb:
+    # A Twitch developer app (dev.twitch.tv). Without both values time to beat is off.
+    client-id: ${IGDB_CLIENT_ID:}
+    client-secret: ${IGDB_CLIENT_SECRET:}
+    base-url: https://api.igdb.com/v4
+    token-base-url: https://id.twitch.tv
+  library:
+    sync-ttl-hours: 24
+    force-sync-cooldown-seconds: 60
+    running-stale-minutes: 5
+    achievement-ttl-hours: 1
+    schema-ttl-days: 30
 
-internal:
-  api-key: ${INTERNAL_API_KEY}
+resilience4j:
+  retry:
+    instances:
+      steamApi:
+        max-attempts: 3
+        wait-duration: 500ms
+        enable-exponential-backoff: true
+        exponential-backoff-multiplier: 2
+        retry-exceptions:
+          - org.springframework.web.client.RestClientException
+          - org.springframework.web.client.ResourceAccessException
+  ratelimiter:
+    instances:
+      steamApi:
+        # Steam allows ~100k req/day. Cap at ~2 req/s to leave headroom for bursts.
+        limit-for-period: 2
+        limit-refresh-period: 1s
+        timeout-duration: 5s
+      igdbApi:
+        # IGDB allows 4 requests/s. Taken per HTTP request.
+        limit-for-period: 4
+        limit-refresh-period: 1s
+        timeout-duration: 10s

src/main/resources/banner.txt

@@ -0,0 +1,18 @@
+        ,----,
+      ,/   .`|                             ,-.----.
+    ,`   .'  :            ,---,.           \    /  \    ,--,                                                         ,----..
+  ;    ;     /          ,'  .'  \          |   :    \ ,--.'|                                        ,---,           /   /   \
+.'___,/    ,'  ,---.  ,---.' .' |          |   |  .\ :|  | :                                      ,---.'|    ,---,.|   :     :  ,---.    __  ,-.
+|    :     |  '   ,'\ |   |  |: |          .   :  |: |:  : '                                      |   | :  ,'  .' |.   |  ;. / '   ,'\ ,' ,'/ /|
+;    |.';  ; /   /   |:   :  :  /   ,---.  |   |   \ :|  ' |     ,--.--.        .--,   ,---.      |   | |,---.'   ,.   ; /--` /   /   |'  | |' | ,---.
+`----'  |  |.   ; ,. ::   |    ;   /     \ |   : .   /'  | |    /       \     /_ ./|  /     \   ,--.__| ||   |    |;   | ;   .   ; ,. :|  |   ,'/     \
+    '   :  ;'   | |: :|   :     \ /    /  |;   | |`-' |  | :   .--.  .-. | , ' , ' : /    /  | /   ,'   |:   :  .' |   : |   '   | |: :'  :  / /    /  |
+    |   |  ''   | .; :|   |   . |.    ' / ||   | ;    '  : |__  \__\/: . ./___/ \: |.    ' / |.   '  /  |:   |.'   .   | '___'   | .; :|  | ' .    ' / |
+    '   :  ||   :    |'   :  '; |'   ;   /|:   ' |    |  | '.'| ," .--.; | .  \  ' |'   ;   /|'   ; |:  |`---'     '   ; : .'|   :    |;  : | '   ;   /|
+    ;   |.'  \   \  / |   |  | ; '   |  / |:   : :    ;  :    ;/  /  ,.  |  \  ;   :'   |  / ||   | '/  '          '   | '/  :\   \  / |  , ; '   |  / |
+    '---'     `----'  |   :   /  |   :    ||   | :    |  ,   /;  :   .'   \  \  \  ;|   :    ||   :    :|          |   :    /  `----'   ---'  |   :    |
+                      |   | ,'    \   \  / `---'.|     ---`-' |  ,     .-./   :  \  \\   \  /  \   \  /             \   \ .'                   \   \  /
+                      `----'       `----'    `---`             `--`---'        \  ' ; `----'    `----'               `---`                      `----'
+                                                                                `--`
+${application.title} ${application.version}
+Powered by Spring Boot ${spring-boot.version}

src/main/resources/db/migration/V1__init_library.sql

@@ -0,0 +1,27 @@
+-- Global Steam game catalog. Shared across users to avoid duplicating metadata.
+CREATE TABLE steam_game (
+    appid         BIGINT       PRIMARY KEY,
+    name          VARCHAR(512) NOT NULL,
+    img_icon_url  VARCHAR(512),
+    last_seen_at  TIMESTAMPTZ  NOT NULL DEFAULT NOW()
+);
+
+-- Per-user ownership and playtime. Soft-delete via removed_at.
+CREATE TABLE user_game (
+    user_id          BIGINT       NOT NULL,
+    appid            BIGINT       NOT NULL REFERENCES steam_game(appid),
+    playtime_minutes INTEGER      NOT NULL DEFAULT 0,
+    first_seen_at    TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
+    last_seen_at     TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
+    removed_at       TIMESTAMPTZ,
+    PRIMARY KEY (user_id, appid)
+);
+CREATE INDEX idx_user_game_user_active ON user_game (user_id) WHERE removed_at IS NULL;
+
+-- Per-user Steam sync state. Owned by Core to avoid coupling Auth schema.
+CREATE TABLE user_steam_sync (
+    user_id          BIGINT       PRIMARY KEY,
+    steam_id         VARCHAR(32)  NOT NULL,
+    last_synced_at   TIMESTAMPTZ,
+    last_sync_status VARCHAR(16)
+);

src/main/resources/db/migration/V2__game_achievements.sql

@@ -0,0 +1,40 @@
+-- Per-game achievement schema (global, shared across users).
+-- Populated on demand from Steam GetSchemaForGame.
+CREATE TABLE game_achievement_schema (
+    appid          BIGINT       NOT NULL,
+    api_name       VARCHAR(256) NOT NULL,
+    display_name   VARCHAR(512),
+    description    VARCHAR(2048),
+    icon_url       VARCHAR(512),
+    icon_gray_url  VARCHAR(512),
+    hidden         BOOLEAN      NOT NULL DEFAULT FALSE,
+    PRIMARY KEY (appid, api_name)
+);
+
+CREATE TABLE game_achievement_schema_meta (
+    appid              BIGINT      PRIMARY KEY,
+    achievements_total INTEGER     NOT NULL DEFAULT 0,
+    has_schema         BOOLEAN     NOT NULL DEFAULT FALSE,
+    refreshed_at       TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Per-user unlock state per game.
+CREATE TABLE user_game_achievement (
+    user_id      BIGINT       NOT NULL,
+    appid        BIGINT       NOT NULL,
+    api_name     VARCHAR(256) NOT NULL,
+    unlocked     BOOLEAN      NOT NULL DEFAULT FALSE,
+    unlocked_at  TIMESTAMPTZ,
+    PRIMARY KEY (user_id, appid, api_name)
+);
+CREATE INDEX idx_uga_user_app ON user_game_achievement (user_id, appid);
+
+-- Per-user per-game refresh marker plus visibility flag (Steam may refuse stats).
+CREATE TABLE user_game_achievement_meta (
+    user_id          BIGINT      NOT NULL,
+    appid            BIGINT      NOT NULL,
+    refreshed_at     TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    stats_visible    BOOLEAN     NOT NULL DEFAULT TRUE,
+    achievements_unlocked INTEGER NOT NULL DEFAULT 0,
+    PRIMARY KEY (user_id, appid)
+);

src/main/resources/db/migration/V3__backlog_fields.sql

@@ -0,0 +1,12 @@
+-- Per-user backlog tracking. The sync sets status only when it inserts a game.
+ALTER TABLE user_game
+    ADD COLUMN status   VARCHAR(16),
+    ADD COLUMN rating   INTEGER  CHECK (rating BETWEEN 1 AND 5),
+    ADD COLUMN notes    VARCHAR(2000),
+    ADD COLUMN priority VARCHAR(8);
+
+UPDATE user_game SET status = CASE WHEN playtime_minutes > 0 THEN 'PLAYING' ELSE 'BACKLOG' END;
+
+ALTER TABLE user_game ALTER COLUMN status SET NOT NULL;
+
+CREATE INDEX idx_user_game_user_status ON user_game (user_id, status) WHERE removed_at IS NULL;

src/main/resources/db/migration/V4__playtime_history.sql

@@ -0,0 +1,21 @@
+-- Minutes played per user, game and day (Europe/Berlin), as the growth of playtime_forever between two syncs.
+-- The first sync of a Steam account is only the baseline and writes no rows.
+CREATE TABLE user_game_playtime_day (
+    user_id BIGINT  NOT NULL,
+    day     DATE    NOT NULL,
+    appid   BIGINT  NOT NULL,
+    minutes INTEGER NOT NULL CHECK (minutes > 0),
+    PRIMARY KEY (user_id, day, appid)
+);
+
+-- The Steam account whose playtime is the baseline for the history: set after a successful sync only.
+-- Growth is recorded only while it equals steam_id, so a failed first sync of a new account cannot turn
+-- that account's whole playtime into one day.
+ALTER TABLE user_steam_sync ADD COLUMN history_steam_id VARCHAR(32);
+
+-- Last request of the user. The nightly sync skips accounts nobody used for a while, e.g. after the user
+-- removed the Steam ID (Core does not learn about that).
+ALTER TABLE user_steam_sync ADD COLUMN user_seen_at TIMESTAMPTZ;
+
+-- Steam's own "last two weeks" playtime, updated on every sync.
+ALTER TABLE user_game ADD COLUMN playtime_2weeks INTEGER NOT NULL DEFAULT 0;

src/main/resources/db/migration/V5__wishlist.sql

@@ -0,0 +1,12 @@
+-- The user's Steam wishlist without the games already owned. The sync replaces it as a whole.
+-- Name and price come from the Steam store at sync time.
+CREATE TABLE wishlist_game (
+    user_id        BIGINT       NOT NULL,
+    appid          BIGINT       NOT NULL,
+    name           VARCHAR(512),
+    added_at       TIMESTAMPTZ,
+    price          VARCHAR(32),
+    original_price VARCHAR(32),
+    discount_pct   INTEGER      NOT NULL DEFAULT 0,
+    PRIMARY KEY (user_id, appid)
+);

src/main/resources/db/migration/V6__game_time_to_beat.sql

@@ -0,0 +1,9 @@
+-- Time to beat per Steam app from IGDB, shared by all users. A row with only NULL times means IGDB has no data;
+-- it is kept so the app is not asked again before the row is stale.
+CREATE TABLE game_time_to_beat (
+    appid              BIGINT      PRIMARY KEY,
+    hastily_minutes    INTEGER,
+    normally_minutes   INTEGER,
+    completely_minutes INTEGER,
+    fetched_at         TIMESTAMPTZ NOT NULL
+);

src/test/java/core_service/architecture/ArchitectureTest.java

@@ -0,0 +1,102 @@
+package core_service.architecture;
+
+import core_service.shared.test.AbstractArchitectureTest;
+import com.tngtech.archunit.core.domain.JavaClass;
+import com.tngtech.archunit.core.importer.ImportOption;
+import com.tngtech.archunit.junit.AnalyzeClasses;
+import com.tngtech.archunit.junit.ArchTest;
+import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.library.dependencies.SlicesRuleDefinition;
+
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.classes;
+import static com.tngtech.archunit.lang.syntax.ArchRuleDefinition.noClasses;
+
+/**
+ * ArchUnit tests to enforce package boundaries in core-service.
+ *
+ * Notes on Core-specific structure (differs from auth-service):
+ *  - JPA entities live in `..domain..` (not `..persistence..`).
+ *  - Repository interfaces live in `..repo..`.
+ *  - `steam_adapter` is an outbound port consumed by feature modules
+ *    (e.g. `library`), so strict slice independence is relaxed for it.
+ */
+@AnalyzeClasses(packages = "core_service", importOptions = ImportOption.DoNotIncludeTests.class)
+class ArchitectureTest extends AbstractArchitectureTest {
+
+    // ===================================================================================
+    // 1. MODULE INDEPENDENCE (Slices)
+    // ===================================================================================
+
+    @ArchTest
+    static final ArchRule modules_should_not_depend_on_each_other = SlicesRuleDefinition.slices()
+            .matching("core_service.modules.(*)..")
+            .should().notDependOnEachOther()
+            .ignoreDependency(
+                    JavaClass.Predicates.resideInAPackage("core_service.modules.library.."),
+                    JavaClass.Predicates.resideInAnyPackage("core_service.modules.steam_adapter..", "core_service.modules.igdb_adapter.."))
+            .because("Feature modules should be isolated; steam_adapter and igdb_adapter are explicit shared ports.");
+
+    @ArchTest
+    static final ArchRule no_cyclic_dependencies = SlicesRuleDefinition.slices()
+            .matching("core_service.(*)..")
+            .should().beFreeOfCycles()
+            .because("Cyclic dependencies make the code unmaintainable and tightly coupled.");
+
+    // ===================================================================================
+    // 2. LAYER DEPENDENCY DIRECTION
+    // ===================================================================================
+
+    @ArchTest
+    static final ArchRule apis_should_not_depend_on_repos = noClasses()
+            .that().resideInAPackage("..api..")
+            .should().dependOnClassesThat().resideInAPackage("..repo..")
+            .because("Controllers must delegate to Services and not access repositories directly.");
+
+    @ArchTest
+    static final ArchRule repos_should_not_depend_on_apis = noClasses()
+            .that().resideInAPackage("..repo..")
+            .should().dependOnClassesThat().resideInAPackage("..api..")
+            .because("Persistence layer must be independent of the API layer.");
+
+    @ArchTest
+    static final ArchRule repos_should_be_interfaces_named_repository = classes()
+            .that().resideInAPackage("..repo..")
+            .should().haveSimpleNameEndingWith("Repository")
+            .because("Repository interfaces are the persistence boundary; naming makes them explicit.");
+
+    // ===================================================================================
+    // 3. SHARED / CONFIGURATION RULES
+    // ===================================================================================
+
+    @ArchTest
+    static final ArchRule shared_should_not_depend_on_modules = noClasses()
+            .that().resideInAPackage("core_service.shared..")
+            .should().dependOnClassesThat().resideInAPackage("core_service.modules..")
+            .because("Shared classes should be independent of specific modules.");
+
+    @ArchTest
+    static final ArchRule modules_should_not_depend_on_global_configuration = noClasses()
+            .that().resideInAPackage("core_service.modules..")
+            .should().dependOnClassesThat().resideInAPackage("core_service.configuration..")
+            .because("Module logic should not depend on global Spring configuration classes.");
+
+    // ===================================================================================
+    // 4. SPRING ANNOTATION CONVENTIONS
+    // ===================================================================================
+
+    @ArchTest
+    static final ArchRule services_should_be_annotated = classes()
+            .that().resideInAPackage("..modules..service..")
+            .and().haveSimpleNameEndingWith("Service")
+            .should().beAnnotatedWith(org.springframework.stereotype.Service.class)
+            .because("Classes named *Service in modules should be registered as Spring @Service beans.");
+
+    @ArchTest
+    static final ArchRule controllers_should_be_annotated = classes()
+            .that().resideInAPackage("..api..")
+            .and().haveSimpleNameEndingWith("Controller")
+            .should().beAnnotatedWith(org.springframework.web.bind.annotation.RestController.class)
+            .orShould().beAnnotatedWith(org.springframework.web.bind.annotation.ControllerAdvice.class)
+            .orShould().beAnnotatedWith(org.springframework.web.bind.annotation.RestControllerAdvice.class)
+            .because("Classes in 'api' package named *Controller should be Spring REST controllers.");
+}

src/test/java/core_service/configuration/security/JwtServiceTest.java

@@ -0,0 +1,136 @@
+package core_service.configuration.security;
+
+import core_service.shared.test.AbstractUnitTest;
+import io.jsonwebtoken.Jwts;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.security.PrivateKey;
+import java.util.Base64;
+import java.util.Date;
+import java.util.Optional;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.lenient;
+
+/**
+ * Tests Core's verify-only JwtService against tokens signed with a matching Ed25519 private key.
+ */
+class JwtServiceTest extends AbstractUnitTest {
+
+    @Mock
+    private JwtConfig jwtConfig;
+
+    private JwtService jwtService;
+    private PrivateKey signingKey;
+
+    @BeforeEach
+    void setUp() throws Exception {
+        KeyPair keyPair = KeyPairGenerator.getInstance("Ed25519").generateKeyPair();
+        signingKey = keyPair.getPrivate();
+        String publicB64 = Base64.getEncoder().encodeToString(keyPair.getPublic().getEncoded());
+
+        lenient().when(jwtConfig.getPublicKey()).thenReturn(publicB64);
+
+        jwtService = new JwtService(jwtConfig);
+        jwtService.init();
+    }
+
+    private String signToken(String userId, String email, Long steamId) {
+        var builder = Jwts.builder()
+                .subject(email)
+                .claim("userId", userId)
+                .issuedAt(new Date())
+                .expiration(new Date(System.currentTimeMillis() + 60_000));
+        if (steamId != null) {
+            builder.claim("steamId", steamId);
+        }
+        return builder.signWith(signingKey, Jwts.SIG.EdDSA).compact();
+    }
+
+    @Test
+    void extractEmail_Success() {
+        var email = "test@example.com";
+        var token = signToken("0815", email, null);
+
+        assertEquals(email, jwtService.extractEmail(token));
+    }
+
+    @Test
+    void extractUserId_Success() {
+        var userId = "0815";
+        var token = signToken(userId, "test@example.com", null);
+
+        assertEquals(userId, jwtService.extractUserId(token));
+    }
+
+    @Test
+    void extractSteamId_Success() {
+        var steamId = 123456789L;
+        var token = signToken("0815", "test@example.com", steamId);
+
+        assertEquals(steamId, jwtService.extractSteamId(token));
+    }
+
+    @Test
+    void isTokenValid_Success() {
+        var token = signToken("0815", "test@example.com", null);
+
+        assertTrue(jwtService.isTokenValid(token));
+    }
+
+    @Test
+    void isTokenValid_Failure_garbage() {
+        assertFalse(jwtService.isTokenValid("not-a-jwt"));
+    }
+
+    @Test
+    void isTokenValid_Failure_wrongKey() throws Exception {
+        KeyPair other = KeyPairGenerator.getInstance("Ed25519").generateKeyPair();
+        String token = Jwts.builder()
+                .subject("test@example.com")
+                .expiration(new Date(System.currentTimeMillis() + 60_000))
+                .signWith(other.getPrivate(), Jwts.SIG.EdDSA)
+                .compact();
+
+        assertFalse(jwtService.isTokenValid(token));
+    }
+
+    private String signTicket(String type, String profileUserId, long expiresInMs) {
+        return Jwts.builder()
+                .subject("public-profile")
+                .claim("typ", type)
+                .claim("profileUserId", profileUserId)
+                .expiration(new Date(System.currentTimeMillis() + expiresInMs))
+                .signWith(signingKey, Jwts.SIG.EdDSA).compact();
+    }
+
+    @Test
+    void verifyProfileTicket_ReturnsTheUser() {
+        assertEquals(Optional.of(42L), jwtService.verifyProfileTicket(signTicket("public-profile", "42", 60_000)));
+    }
+
+    @Test
+    void verifyProfileTicket_RejectsLoginTokensOtherTypesExpiredAndForeignTickets() throws Exception {
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket(signToken("42", "a@b.de", null)));
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket(signTicket("something-else", "42", 60_000)));
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket(signTicket("public-profile", "42", -1_000)));
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket(signTicket("public-profile", "not-a-number", 60_000)));
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket("garbage"));
+
+        PrivateKey otherKey = KeyPairGenerator.getInstance("Ed25519").generateKeyPair().getPrivate();
+        String foreign = Jwts.builder().claim("typ", "public-profile").claim("profileUserId", "42")
+                .expiration(new Date(System.currentTimeMillis() + 60_000)).signWith(otherKey, Jwts.SIG.EdDSA).compact();
+        assertEquals(Optional.empty(), jwtService.verifyProfileTicket(foreign));
+    }
+
+    @Test
+    void isTokenValid_ProfileTicketIsNoLogin() {
+        assertFalse(jwtService.isTokenValid(signTicket("public-profile", "42", 60_000)));
+    }
+}

src/test/java/core_service/configuration/security/PublicEndpointsTest.java

@@ -0,0 +1,93 @@
+package core_service.configuration.security;
+
+import io.jsonwebtoken.Jwts;
+import org.junit.jupiter.api.Tag;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.testcontainers.service.connection.ServiceConnection;
+import org.springframework.boot.webmvc.test.autoconfigure.AutoConfigureMockMvc;
+import org.springframework.test.context.DynamicPropertyRegistry;
+import org.springframework.test.context.DynamicPropertySource;
+import org.springframework.test.web.servlet.MockMvc;
+import org.testcontainers.containers.PostgreSQLContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+
+import java.security.KeyPair;
+import java.security.KeyPairGenerator;
+import java.util.Base64;
+import java.util.Date;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+/**
+ * Runs with the production security filter (not the dev profile, which injects a dummy user).
+ */
+@Tag("IntegrationTest")
+@SpringBootTest
+@AutoConfigureMockMvc
+@Testcontainers
+class PublicEndpointsTest {
+
+    @Container
+    @ServiceConnection
+    static PostgreSQLContainer<?> postgres = new PostgreSQLContainer<>("postgres:17-alpine");
+
+    private static final KeyPair KEYS = generateKeys();
+
+    private static KeyPair generateKeys() {
+        try {
+            return KeyPairGenerator.getInstance("Ed25519").generateKeyPair();
+        } catch (Exception e) {
+            throw new IllegalStateException(e);
+        }
+    }
+
+    @DynamicPropertySource
+    static void properties(DynamicPropertyRegistry registry) {
+        registry.add("security.jwt.public-key", () -> Base64.getEncoder().encodeToString(KEYS.getPublic().getEncoded()));
+        registry.add("app.steam.api-key", () -> "test-key");
+    }
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    void healthIsPublicWithoutDetails() throws Exception {
+        mockMvc.perform(get("/actuator/health"))
+                .andExpect(status().isOk())
+                .andExpect(jsonPath("$.status").value("UP"))
+                .andExpect(jsonPath("$.components").doesNotExist());
+    }
+
+    @ParameterizedTest
+    @ValueSource(strings = {"/actuator/prometheus", "/api/steam/test/76561198000000001", "/internal/anything"})
+    void endpointIsNotPublic(String path) throws Exception {
+        int status = mockMvc.perform(get(path)).andReturn().getResponse().getStatus();
+        assertTrue(Set.of(401, 403).contains(status), path + " answered " + status);
+    }
+
+    @Test
+    void profileTicketIsNoLogin() throws Exception {
+        String ticket = Jwts.builder().subject("public-profile").claim("typ", "public-profile").claim("profileUserId", "1")
+                .claim("userId", "1").expiration(new Date(System.currentTimeMillis() + 60_000))
+                .signWith(KEYS.getPrivate(), Jwts.SIG.EdDSA).compact();
+
+        int status = mockMvc.perform(get("/api/library/games-count").header("Authorization", "Bearer " + ticket))
+                .andReturn().getResponse().getStatus();
+        assertTrue(Set.of(401, 403).contains(status), "ticket as login answered " + status);
+    }
+
+    @Test
+    void publicProfileEndpointIsPublic() throws Exception {
+        mockMvc.perform(get("/api/public/profiles/library")).andExpect(status().isUnauthorized())
+                .andExpect(jsonPath("$.code").value("INVALID_TICKET"));
+    }
+}