Added new endpoints to sync the list of games from steam if a user logged in.

src/main/resources/application.yml

@@ -43,4 +43,27 @@ app:
   steam:
     api-key: ${STEAM_API_KEY}
     base-url: https://api.steampowered.com
-    imageService-url: https://cdn.cloudflare.steamstatic.com/steam/apps/
+    imageService-url: https://cdn.cloudflare.steamstatic.com/steam/apps/
+  library:
+    sync-ttl-hours: 24
+    force-sync-cooldown-seconds: 60
+    running-stale-minutes: 5
+
+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

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)
+);