fix(downloads): accept optional completed_at in complete_download to preserve original timestamps

py/routes/handlers/model_handlers.py

@@ -1785,6 +1785,8 @@ class ModelDownloadHandler:
                 bytes_downloaded = 0
             total_bytes_raw = request.query.get("total_bytes")
             total_bytes = int(total_bytes_raw) if total_bytes_raw else None
+            completed_at_raw = request.query.get("completed_at")
+            completed_at = float(completed_at_raw) if completed_at_raw else None
 
             service = await DownloadQueueService.get_instance()
             item = await service.complete_download(
@@ -1794,6 +1796,7 @@ class ModelDownloadHandler:
                 file_path=file_path,
                 bytes_downloaded=bytes_downloaded,
                 total_bytes=total_bytes,
+                completed_at=completed_at,
             )
             if item is None:
                 return web.json_response(

py/services/download_queue_service.py

@@ -349,6 +349,7 @@ class DownloadQueueService:
         file_path: Optional[str] = None,
         bytes_downloaded: int = 0,
         total_bytes: Optional[int] = None,
+        completed_at: Optional[float] = None,
     ) -> Optional[dict[str, Any]]:
         """Atomically move a download from the queue into the history table.
 
@@ -356,6 +357,9 @@ class DownloadQueueService:
         queue, and inserts a corresponding history entry with the given
         terminal status (``completed``, ``failed``, or ``canceled``).
 
+        When *completed_at* is provided it is used as the completion
+        timestamp; otherwise ``time.time()`` is used.
+
         Returns the original queue record (before deletion) on success,
         or ``None`` if the download was not found in the queue.
         """
@@ -368,7 +372,7 @@ class DownloadQueueService:
             if row is None:
                 return None
 
-            now = time.time()
+            now = completed_at if completed_at is not None else time.time()
             conn.execute(
                 "DELETE FROM download_queue WHERE download_id = ?",
                 (download_id,),