build(docker): layer Spring Boot service images

deploy/docker/Dockerfile

@@ -1,4 +1,12 @@
 ARG BASE_IMAGE=docker.m.daocloud.io/library/eclipse-temurin:17-jre-alpine
+FROM ${BASE_IMAGE} AS extractor
+
+WORKDIR /workspace
+
+ARG JAR_FILE
+COPY ${JAR_FILE} app.jar
+RUN java -Djarmode=layertools -jar app.jar extract
+
 FROM ${BASE_IMAGE}
 
 RUN addgroup -S app \
@@ -9,8 +17,11 @@ WORKDIR /app
 # 预建镜像内运行时数据和日志目录并归属 app 用户；宿主机 bind mount 的属主需在部署前单独设置为 UID 10001。
 RUN mkdir -p /data/files /app/logs && chown -R app:app /data /app/logs
 
-ARG JAR_FILE
-COPY --chown=app:app ${JAR_FILE} /app/app.jar
+# 依赖层稳定、业务代码层高频变化；Registry 只需传输实际变化的 Layer。
+COPY --from=extractor --chown=app:app /workspace/dependencies/ ./
+COPY --from=extractor --chown=app:app /workspace/spring-boot-loader/ ./
+COPY --from=extractor --chown=app:app /workspace/snapshot-dependencies/ ./
+COPY --from=extractor --chown=app:app /workspace/application/ ./
 
 USER app
 
@@ -22,4 +33,4 @@ EXPOSE 8080
 HEALTHCHECK --interval=30s --timeout=5s --start-period=60s --retries=3 \
     CMD busybox wget -q -O /dev/null "http://127.0.0.1:${SERVER_PORT}/actuator/health" || exit 1
 
-ENTRYPOINT ["sh", "-c", "exec java $JAVA_OPTS -jar /app/app.jar"]
+ENTRYPOINT ["sh", "-c", "exec java $JAVA_OPTS org.springframework.boot.loader.launch.JarLauncher"]