fix(upload): remove explicit Content-Type header so browser sets multipart boundary

Without boundary multer receives undefined file. Also add guards in
backend parse/upload to avoid crash if file is missing.

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

backend/services/admin-service/src/interface/http/controllers/admin-version.controller.ts

@@ -101,6 +101,9 @@ export class AdminVersionController {
     },
     @Req() req: any,
   ) {
+    if (!file) {
+      return { code: 400, message: 'No file uploaded — check Content-Type boundary' };
+    }
     // Parse package to extract metadata (auto-fill when not provided)
     const parsedInfo = await this.packageParser.parse(file.buffer, file.originalname);
 
@@ -152,6 +155,9 @@ export class AdminVersionController {
   @ApiConsumes('multipart/form-data')
   @ApiOperation({ summary: 'Parse APK/IPA without saving (preview metadata)' })
   async parsePackage(@UploadedFile() file: Express.Multer.File) {
+    if (!file) {
+      return { code: 400, message: 'No file uploaded — check Content-Type boundary' };
+    }
     const info = await this.packageParser.parse(file.buffer, file.originalname);
     return { code: 0, data: info };
   }

frontend/admin-web/src/views/app-versions/AppVersionManagementPage.tsx

@@ -325,7 +325,6 @@ const UploadModal: React.FC<{
       const info = await apiClient.post<{
         versionCode?: number; versionName?: string; minSdkVersion?: string;
       }>('/api/v1/admin/versions/parse', formData, {
-        headers: { 'Content-Type': 'multipart/form-data' },
         timeout: 300000,
       });
       console.log('[Upload] Parse result:', info);
@@ -359,7 +358,6 @@ const UploadModal: React.FC<{
       formData.append('isForceUpdate', String(isForceUpdate));
 
       const result = await apiClient.post('/api/v1/admin/versions/upload', formData, {
-        headers: { 'Content-Type': 'multipart/form-data' },
         timeout: 300000,
       });
       console.log('[Upload] Success:', result);