feat: implement background processing for binary attachments in Obsidian plugin

- Added a new Celery task for indexing non-markdown attachments.
- Enhanced the Obsidian plugin schema to support binary attachments.
- Updated routes to enqueue binary attachments for background processing.
- Improved metadata handling for binary attachments during indexing.
- Added tests for binary attachment processing and validation.

surfsense_backend/app/tasks/celery_tasks/obsidian_tasks.py

@@ -0,0 +1,59 @@
+"""Celery tasks for Obsidian plugin background processing."""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+
+from app.celery_app import celery_app
+from app.db import SearchSourceConnector
+from app.schemas.obsidian_plugin import NotePayload
+from app.services.obsidian_plugin_indexer import upsert_note
+from app.tasks.celery_tasks import get_celery_session_maker
+
+logger = logging.getLogger(__name__)
+
+
+@celery_app.task(name="index_obsidian_attachment", bind=True)
+def index_obsidian_attachment_task(
+    self,
+    connector_id: int,
+    payload_data: dict,
+    user_id: str,
+) -> None:
+    """Process one Obsidian non-markdown attachment asynchronously."""
+    loop = asyncio.new_event_loop()
+    asyncio.set_event_loop(loop)
+    try:
+        loop.run_until_complete(
+            _index_obsidian_attachment(
+                connector_id=connector_id,
+                payload_data=payload_data,
+                user_id=user_id,
+            )
+        )
+    finally:
+        loop.close()
+
+
+async def _index_obsidian_attachment(
+    *,
+    connector_id: int,
+    payload_data: dict,
+    user_id: str,
+) -> None:
+    async with get_celery_session_maker()() as session:
+        connector = await session.get(SearchSourceConnector, connector_id)
+        if connector is None:
+            logger.warning(
+                "obsidian attachment task skipped: connector %s not found", connector_id
+            )
+            return
+
+        payload = NotePayload.model_validate(payload_data)
+        await upsert_note(
+            session,
+            connector=connector,
+            payload=payload,
+            user_id=user_id,
+        )