Initial project setup: CI, Docker & configs

Add project bootstrap for build, CI/CD, and local development. Introduces Maven Wrapper (mvnw, mvnw.cmd, .mvn/wrapper), multi-stage Dockerfile, docker-compose files (compose.yaml, docker-compose.dev.yml), .env, banner and README. Adds Gitea Actions workflow to build, test and push container images. Update application.yml (port -> 8090, virtual threads, API versioning, management/actuator/prometheus settings, Steam API config) and add application-dev.yml for local overrides. Extend pom.xml with caching, observability (actuator, micrometer/prometheus), testing/dev dependencies (testcontainers, devtools, additional spring test modules) to support CI and local testing.

pom.xml

@@ -40,6 +40,7 @@
             <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>
@@ -75,6 +76,8 @@
             <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 +87,14 @@
             <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 +110,48 @@
             <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 +159,7 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
+
     <build>
         <plugins>
             <plugin>