fix download

backend/src/app/api/v1/batch.py

@@ -2,6 +2,7 @@
 
 import os
 from pathlib import Path
+from urllib.parse import quote
 
 from fastapi import APIRouter, BackgroundTasks, status
 from fastapi.responses import FileResponse
@@ -19,6 +20,28 @@ from app.services.batch_operations_service import BatchOperationsService
 router = APIRouter(prefix="/batch", tags=["batch"])
 
 
+def make_content_disposition(filename: str) -> str:
+    """
+    Create Content-Disposition header value with proper encoding for non-ASCII filenames.
+
+    Uses RFC 5987/2231 encoding to support UTF-8 filenames.
+
+    Args:
+        filename: Original filename (may contain non-ASCII characters)
+
+    Returns:
+        Properly formatted Content-Disposition header value
+    """
+    # ASCII-safe fallback (replace non-ASCII with underscore)
+    ascii_filename = filename.encode("ascii", errors="replace").decode("ascii")
+
+    # UTF-8 encoded filename (RFC 5987)
+    utf8_filename = quote(filename.encode("utf-8"))
+
+    # Return both for maximum compatibility
+    return f"attachment; filename=\"{ascii_filename}\"; filename*=UTF-8''{utf8_filename}"
+
+
 @router.post("/delete", response_model=BatchDeleteResponse)
 async def batch_delete(
     request: BatchDeleteRequest,
@@ -119,7 +142,7 @@ async def batch_download(
         media_type="application/zip",
         filename=filename,
         headers={
-            "Content-Disposition": f'attachment; filename="{filename}"',
+            "Content-Disposition": make_content_disposition(filename),
         },
     )
 
@@ -169,6 +192,6 @@ async def download_folder(
         media_type="application/zip",
         filename=filename,
         headers={
-            "Content-Disposition": f'attachment; filename="{filename}"',
+            "Content-Disposition": make_content_disposition(filename),
         },
     )