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

src/main/java/com/gmp/mock/controller/DocxController.java

@@ -1,19 +1,19 @@
 package com.gmp.mock.controller;
 
-import java.io.IOException;
-
 import jakarta.validation.Valid;
 
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
-import com.gmp.mock.dto.ApiResponse;
-import com.gmp.mock.dto.DocxExportData;
 import com.gmp.mock.dto.DocxExportRequest;
 import com.gmp.mock.service.DocxService;
+import com.gmp.mock.service.DocxService.ExportResult;
 
 @RestController
 @RequestMapping("/api/docx")
@@ -26,11 +26,18 @@ public class DocxController {
     }
 
     @PostMapping("/export")
-    public ResponseEntity<ApiResponse<DocxExportData>> exportDocx(@Valid @RequestBody DocxExportRequest request) throws IOException {
-        DocxExportData data = docxService.export(request.getExportId());
-        if (data == null) {
-            return ResponseEntity.ok(ApiResponse.error(404, "模板不存在"));
-        }
-        return ResponseEntity.ok(ApiResponse.success(data));
+    public ResponseEntity<StreamingResponseBody> exportDocx(@Valid @RequestBody DocxExportRequest request) {
+
+        ExportResult result = docxService.export(request.getExportId());
+
+        StreamingResponseBody stream = outputStream ->
+                result.writer().write(outputStream);
+
+        return ResponseEntity.ok()
+                .contentType(MediaType.parseMediaType(
+                        "application/vnd.openxmlformats-officedocument.wordprocessingml.document"))
+                .header(HttpHeaders.CONTENT_DISPOSITION,
+                        "attachment; filename=\"" + result.fileName() + "\"")
+                .body(stream);
     }
 }