Add Docker support with CI workflow and runtime configuration

- Added `Dockerfile` to build a Docker image for the JavadocViewerService.
- Implemented a Gitea-based CI workflow (`deploy-image.yml`) to build and push the Docker image.
- Updated `settings.local.json` to expand permissions for the service.
- Included `-DskipTests` to Maven arguments in `JavadocService.java`.

Dockerfile

@@ -0,0 +1,36 @@
+# Stage 1: Build the JAR using Maven
+FROM maven:3.9-eclipse-temurin-17 AS builder
+
+LABEL org.opencontainers.image.description="JavadocViewerService serves and manages Javadoc documentation from Git repositories."
+
+WORKDIR /build
+
+# Copy pom.xml and download dependencies first (for Docker cache)
+COPY pom.xml .
+RUN mvn dependency:go-offline
+
+# Copy the full source tree and build the application
+COPY src ./src
+RUN mvn clean package -DskipTests
+
+# Stage 2: Minimal runtime image
+FROM eclipse-temurin:17-jdk-jammy
+
+WORKDIR /app
+
+# Optional: add tini to manage signals properly
+RUN apt-get update && apt-get install -y tini && rm -rf /var/lib/apt/lists/*
+
+# Create a non-root user
+RUN useradd -m jvsuser
+USER jvsuser
+
+# Copy the built jar from the builder stage
+COPY --from=builder /build/target/*.jar /app/jvs.jar
+
+VOLUME ["/app/javadoc-storage", "/app/database"]
+
+EXPOSE 8080
+
+ENTRYPOINT ["/usr/bin/tini", "--"]
+CMD ["java", "-jar", "jvs.jar"]