ci: pipeline Gitea Actions build & push Docker sur push main

- Dockerfile multi-stage (build eclipse-temurin:25-jdk → runtime)
- CI : tests via actions/setup-java puis build & push vers registry Gitea
- Trigger Watchtower après push sur main
- CLAUDE.md + rules projet (.claude/rules/)
- Version build.gradle : 0.0.1-SNAPSHOT → 0.0.1

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,18 @@
+FROM eclipse-temurin:25-jdk AS builder
+WORKDIR /workspace
+
+COPY gradlew .
+COPY gradle/ gradle/
+COPY build.gradle settings.gradle gradle.properties ./
+RUN ./gradlew dependencies --no-daemon -q
+
+COPY src/ src/
+RUN ./gradlew bootJar --no-daemon -x test
+
+FROM eclipse-temurin:25-jdk AS runtime
+WORKDIR /app
+
+COPY --from=builder /workspace/build/libs/olhar-api.jar app.jar
+
+EXPOSE 8080
+ENTRYPOINT ["java", "-jar", "app.jar"]