Add comprehensive processing logging system

- Added database logging to all major processing tasks
- Created API endpoints for retrieving processing logs
- Updated frontend to display processing logs per file
- Logging includes: process_document, convert_to_pdf, extract_metadata_with_gpt, embed_metadata_into_pdf, finalize_document_storage, send_to_all_destinations

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/tasks/finalize_document_storage.py

@@ -1,5 +1,7 @@
 #!/usr/bin/env python3
 
+import logging
+import os
 from app.config import settings
 from app.tasks.retry_config import BaseTaskWithRetry
 # Import the shared Celery instance
@@ -7,17 +9,36 @@ from app.celery_app import celery
 
 # 1) Import the aggregator task
 from app.tasks.send_to_all import send_to_all_destinations
+from app.utils import log_task_progress
+from app.database import SessionLocal
+from app.models import FileRecord
+
+logger = logging.getLogger(__name__)
 
 
-@celery.task(base=BaseTaskWithRetry)
-def finalize_document_storage(original_file: str, processed_file: str, metadata: dict):
+@celery.task(base=BaseTaskWithRetry, bind=True)
+def finalize_document_storage(self, original_file: str, processed_file: str, metadata: dict):
     """
     Final storage step after embedding metadata.
     We will now call 'send_to_all_destinations' to push the final PDF to Dropbox/Nextcloud/Paperless.
     """
-    print(f"[INFO] Finalizing document storage for {processed_file}")
+    task_id = self.request.id
+    logger.info(f"[{task_id}] Finalizing document storage for {processed_file}")
+    log_task_progress(task_id, "finalize_document_storage", "in_progress", f"Finalizing: {os.path.basename(processed_file)}")
+    
+    # Get file_id from database
+    file_id = None
+    with SessionLocal() as db:
+        # Try to find by the processed file path first
+        file_record = db.query(FileRecord).filter(
+            FileRecord.local_filename.like(f"%{os.path.basename(original_file)}%")
+        ).first()
+        if file_record:
+            file_id = file_record.id
 
     # 2) Enqueue uploads to all destinations (Dropbox, Nextcloud, Paperless)
+    logger.info(f"[{task_id}] Queueing uploads to all destinations")
+    log_task_progress(task_id, "finalize_document_storage", "success", "Queuing uploads to destinations", file_id=file_id)
     send_to_all_destinations.delay(processed_file)
 
     return {