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/tasks/upload_to_webdav.py

@@ -1,21 +1,24 @@
 #!/usr/bin/env python3
 
+import logging
 import os
-import requests
 from urllib.parse import urljoin
+
+import requests
+
+from app.celery_app import celery
 from app.config import settings
 from app.tasks.retry_config import BaseTaskWithRetry
-from app.celery_app import celery
 from app.utils import log_task_progress
-import logging
 
 logger = logging.getLogger(__name__)
 
+
 @celery.task(base=BaseTaskWithRetry, bind=True)
 def upload_to_webdav(self, file_path: str, file_id: int = None):
     """
     Uploads a file to a WebDAV server in the configured folder.
-    
+
     Args:
         file_path: Path to the file to upload
         file_id: Optional file ID to associate with logs
@@ -23,7 +26,11 @@ def upload_to_webdav(self, file_path: str, file_id: int = None):
     task_id = self.request.id
     logger.info(f"[{task_id}] Starting WebDAV upload: {file_path}")
     log_task_progress(
-        task_id, "upload_to_webdav", "in_progress", f"Uploading to WebDAV: {os.path.basename(file_path)}", file_id=file_id
+        task_id,
+        "upload_to_webdav",
+        "in_progress",
+        f"Uploading to WebDAV: {os.path.basename(file_path)}",
+        file_id=file_id,
     )
 
     if not os.path.exists(file_path):
@@ -47,13 +54,13 @@ def upload_to_webdav(self, file_path: str, file_id: int = None):
     # Ensure folder doesn't have leading slash if we're joining it to the base URL
     if webdav_folder and webdav_folder.startswith("/"):
         webdav_folder = webdav_folder[1:]
-    
+
     # Join the base URL and folder path
     target_url = urljoin(settings.webdav_url, webdav_folder)
     # Ensure URL ends with a slash for proper joining with filename
     if not target_url.endswith("/"):
         target_url += "/"
-    
+
     # Construct final URL with filename
     webdav_url = urljoin(target_url, filename)
 
@@ -65,20 +72,22 @@ def upload_to_webdav(self, file_path: str, file_id: int = None):
                 auth=(settings.webdav_username, settings.webdav_password),
                 data=file_data,
                 verify=settings.webdav_verify_ssl if hasattr(settings, "webdav_verify_ssl") else True,
-                timeout=settings.http_request_timeout
+                timeout=settings.http_request_timeout,
             )
 
         # Check if upload was successful
         if response.status_code in (200, 201, 204):
             logger.info(f"[{task_id}] Successfully uploaded {filename} to WebDAV at {webdav_url}.")
-            log_task_progress(task_id, "upload_to_webdav", "success", f"Uploaded to WebDAV: {filename}", file_id=file_id)
+            log_task_progress(
+                task_id, "upload_to_webdav", "success", f"Uploaded to WebDAV: {filename}", file_id=file_id
+            )
             return {"status": "Completed", "file": file_path, "url": webdav_url}
         else:
             error_msg = f"Failed to upload {filename} to WebDAV: {response.status_code} - {response.text}"
             logger.error(f"[{task_id}] {error_msg}")
             log_task_progress(task_id, "upload_to_webdav", "failure", error_msg, file_id=file_id)
             raise Exception(error_msg)
-    
+
     except Exception as e:
         error_msg = f"Error uploading {filename} to WebDAV: {str(e)}"
         logger.error(f"[{task_id}] {error_msg}")