refactor: streaming download, Git LFS templates, deploy workflow

- Replace base64 JSON response with StreamingResponseBody (zero-buffer)
- Error responses return JSON via GlobalExceptionHandler (400/404)
- Add git-lfs track for *.docx to keep repo lean
- Add deploy/deploy.sh: one-click build + restart
- Add deploy/clean-lfs.sh: periodic LFS cache cleanup
- Add deploy/gmp-service.service: systemd service unit
- Remove unused ApiResponse and DocxExportData DTOs
- Fix build.sh/run.sh jar name (gmp-mock-service -> gmp-service)
- Add TemplateNotFoundException for missing templates

deploy/run.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-JAR_PATH="target/gmp-mock-service.jar"
+JAR_PATH="target/gmp-service.jar"
 
 if [ ! -f "$JAR_PATH" ]; then
     echo "JAR 文件不存在，请先执行 build.sh 进行构建"