fix(api): run single-video delete/update off the event loop

invokeai/app/api/routers/videos.py

@@ -346,8 +346,12 @@ async def upload_video(
             pass
 
 
+# Declared sync (`def`, not `async def`) so FastAPI runs it in the threadpool: every call
+# below is blocking SQLite/filesystem work, which would stall the event loop — and with it
+# every other request and socket event — for the duration of the delete. The batch
+# siblings below are sync for the same reason.
 @videos_router.delete("/i/{video_name}", operation_id="delete_video", response_model=DeleteVideosResult)
-async def delete_video(
+def delete_video(
     current_user: CurrentUserOrDefault,
     video_name: str = PathParam(description="The name of the video to delete"),
 ) -> DeleteVideosResult:
@@ -451,8 +455,9 @@ def delete_uncategorized_videos(
     )
 
 
+# Sync for the same reason as delete_video: the update is a blocking SQLite write.
 @videos_router.patch("/i/{video_name}", operation_id="update_video", response_model=VideoDTO)
-async def update_video(
+def update_video(
     current_user: CurrentUserOrDefault,
     video_name: str = PathParam(description="The name of the video to update"),
     video_changes: VideoRecordChanges = Body(description="The changes to apply to the video"),

tests/app/routers/test_videos_multiuser.py

@@ -28,10 +28,12 @@
     VideoNamesBatch,
     _is_mp4_file,
     delete_uncategorized_videos,
+    delete_video,
     delete_videos_from_list,
     get_video_thumbnail,
     star_videos_in_list,
     unstar_videos_in_list,
+    update_video,
 )
 from invokeai.app.api_app import app
 from invokeai.app.services.invoker import Invoker
@@ -932,3 +934,19 @@ def test_delete_uncategorized_videos_is_offloaded_by_fastapi() -> None:
 )
 def test_video_batch_mutations_are_offloaded_by_fastapi(handler: Any) -> None:
     assert not inspect.iscoroutinefunction(handler)
+
+
+@pytest.mark.parametrize(
+    "handler",
+    [
+        delete_video,
+        update_video,
+    ],
+)
+def test_single_video_mutations_are_offloaded_by_fastapi(handler: Any) -> None:
+    """Single-item mutations do blocking SQLite/disk work, same as their batch siblings.
+
+    Declared ``async def``, they would run that work directly on the event loop and stall
+    every other request and socket event until the delete/update finished.
+    """
+    assert not inspect.iscoroutinefunction(handler)