style: fix all flake8 linter errors across app/ directory

- Run Black formatter and isort on all app/ files
- Remove unused imports (F401) across multiple files
- Add # noqa: F401 for intentional re-exports in celery_worker.py,
  tasks/__init__.py, utils.py, frontend.py, views/base.py
- Fix f-strings without placeholders (F541) in azure.py, notification.py,
  check_credentials.py, upload_to_onedrive.py, settings.py
- Fix bare except (E722) in upload_to_sftp.py
- Fix block comment format (E265) in models.py
- Move imports to top of file to fix E402 in celery_app.py, celery_worker.py
- Fix line-too-long (E501) by wrapping strings in multiple files
- Remove unused variable (F841) in upload_to_nextcloud.py

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

app/views/google_drive.py

@@ -1,14 +1,17 @@
 """
 Google Drive integration views for setup and OAuth callback.
 """
-from fastapi import Request
-from fastapi.responses import RedirectResponse
+
 import urllib.parse
 
-from app.views.base import APIRouter, templates, require_login, settings
+from fastapi import Request
+from fastapi.responses import RedirectResponse
+
+from app.views.base import APIRouter, require_login, settings, templates
 
 router = APIRouter()
 
+
 @router.get("/google-drive-setup")
 @require_login
 async def google_drive_setup_page(request: Request):
@@ -17,24 +20,24 @@ async def google_drive_setup_page(request: Request):
     Shows configuration status and setup instructions.
     """
     # Check if using OAuth
-    use_oauth = getattr(settings, 'google_drive_use_oauth', False)
-    
+    use_oauth = getattr(settings, "google_drive_use_oauth", False)
+
     # Check Google Drive OAuth configuration
-    oauth_configured = bool(settings.google_drive_client_id and 
-                         settings.google_drive_client_secret and 
-                         settings.google_drive_refresh_token)
-    
+    oauth_configured = bool(
+        settings.google_drive_client_id and settings.google_drive_client_secret and settings.google_drive_refresh_token
+    )
+
     # Check Google Drive service account configuration
     sa_configured = bool(settings.google_drive_credentials_json)
-    
+
     # Overall configuration status
     is_configured = (use_oauth and oauth_configured) or (not use_oauth and sa_configured)
-    
+
     if settings.google_drive_folder_id:
         is_configured = is_configured and True
     else:
         is_configured = False
-    
+
     # Get configuration values to display status (hide sensitive values)
     return templates.TemplateResponse(
         "google_drive.html",
@@ -51,10 +54,11 @@ async def google_drive_setup_page(request: Request):
             "refresh_token": bool(settings.google_drive_refresh_token),
             "refresh_token_value": settings.google_drive_refresh_token or "",
             "folder_id": settings.google_drive_folder_id or "",
-            "has_credentials_json": bool(settings.google_drive_credentials_json)
-        }
+            "has_credentials_json": bool(settings.google_drive_credentials_json),
+        },
     )
 
+
 @router.get("/google-drive-callback")
 @require_login
 async def google_drive_callback(request: Request, code: str = None, error: str = None, state: str = None):
@@ -63,48 +67,33 @@ async def google_drive_callback(request: Request, code: str = None, error: str =
     Now automatically exchanges the code for a token and saves it to the configuration.
     """
     if error:
-        return templates.TemplateResponse(
-            "google_drive_callback_error.html",
-            {"request": request, "error": error}
-        )
-    
+        return templates.TemplateResponse("google_drive_callback_error.html", {"request": request, "error": error})
+
     if not code:
         return templates.TemplateResponse(
             "google_drive_callback_error.html",
-            {"request": request, "error": "No authorization code received from Google"}
+            {"request": request, "error": "No authorization code received from Google"},
         )
-    
+
     # Display the processing page with automatic token exchange
-    return templates.TemplateResponse(
-        "google_drive_callback.html",
-        {
-            "request": request, 
-            "code": code,
-            "state": state
-        }
-    )
+    return templates.TemplateResponse("google_drive_callback.html", {"request": request, "code": code, "state": state})
+
 
 @router.get("/google-drive-auth-start")
 @require_login
-async def google_drive_auth_start(
-    request: Request, 
-    client_id: str,
-    redirect_uri: str = None
-):
+async def google_drive_auth_start(request: Request, client_id: str, redirect_uri: str = None):
     """
     Start the Google Drive OAuth flow by redirecting to Google's authorization page.
     """
     if not redirect_uri:
         redirect_uri = f"{request.url.scheme}://{request.url.netloc}/google-drive-callback"
-    
+
     # Create the authorization URL with required scopes
     # Use only drive.file scope to minimize required permissions
-    scopes = [
-        "https://www.googleapis.com/auth/drive.file"  # Access to files created or opened by the app
-    ]
-    
-    scope_str = urllib.parse.quote(' '.join(scopes))
-    
+    scopes = ["https://www.googleapis.com/auth/drive.file"]  # Access to files created or opened by the app
+
+    scope_str = urllib.parse.quote(" ".join(scopes))
+
     auth_url = (
         f"https://accounts.google.com/o/oauth2/auth"
         f"?client_id={client_id}"
@@ -114,5 +103,5 @@ async def google_drive_auth_start(
         f"&access_type=offline"
         f"&prompt=consent"  # Force to show consent screen to get refresh token
     )
-    
+
     return RedirectResponse(url=auth_url)