feat: track designer downloads and notifications

backend/app/api/upload.py

@@ -119,6 +119,7 @@ async def upload_work(
     description: Optional[str] = Form(None, description="作品描述"),
     category: str = Form(..., description="作品分类"),
     tags: Optional[str] = Form(None, description="标签，逗号分隔"),
+    designer_name: Optional[str] = Form(None, description="归属设计师"),
     price: float = Form(..., ge=0, description="作品价格"),
     current_user: User = Depends(get_current_user),
     db: Session = Depends(get_db)
@@ -189,6 +190,7 @@ async def upload_work(
             tags_str = ",".join(tags_list)  # 转成逗号分隔的字符串
         else:
             tags_str = None
+        resolved_designer = str(designer_name or "").strip() or current_user.nickname or current_user.phone
         
         # 创建数据库记录 - 修复所有字段问题
         work = Work(
@@ -197,7 +199,7 @@ async def upload_work(
             category=category,
             tags=tags_str,  # 修复：使用字符串而不是列表
             price=price,
-            designer=current_user.nickname or current_user.phone,
+            designer=resolved_designer,
             original_image=f"/uploads/original/{timestamp}/{original_filename}",
             thumbnail_image=f"/uploads/thumbnail/{timestamp}/{thumb_filename}",
             watermarked_image=f"/uploads/watermarked/{timestamp}/{watermarked_filename}"