feat: add folder management features including creation, deletion, and organization of documents within folders

surfsense_backend/app/tasks/celery_tasks/document_tasks.py

@@ -133,6 +133,51 @@ async def _delete_document_background(document_id: int) -> None:
             await session.commit()
 
 
+@celery_app.task(
+    name="delete_folder_documents_background",
+    bind=True,
+    autoretry_for=(Exception,),
+    retry_backoff=True,
+    retry_backoff_max=300,
+    max_retries=5,
+)
+def delete_folder_documents_task(self, document_ids: list[int]):
+    """Celery task to batch-delete documents orphaned by folder deletion."""
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        loop.run_until_complete(_delete_folder_documents(document_ids))
+    finally:
+        loop.close()
+
+
+async def _delete_folder_documents(document_ids: list[int]) -> None:
+    """Delete chunks in batches, then document rows for each orphaned document."""
+    from sqlalchemy import delete as sa_delete, select
+
+    from app.db import Chunk, Document
+
+    async with get_celery_session_maker()() as session:
+        batch_size = 500
+        for doc_id in document_ids:
+            while True:
+                chunk_ids_result = await session.execute(
+                    select(Chunk.id)
+                    .where(Chunk.document_id == doc_id)
+                    .limit(batch_size)
+                )
+                chunk_ids = chunk_ids_result.scalars().all()
+                if not chunk_ids:
+                    break
+                await session.execute(sa_delete(Chunk).where(Chunk.id.in_(chunk_ids)))
+                await session.commit()
+
+            doc = await session.get(Document, doc_id)
+            if doc:
+                await session.delete(doc)
+                await session.commit()
+
+
 @celery_app.task(
     name="delete_search_space_background",
     bind=True,