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/utils/config_loader.py

@@ -9,6 +9,7 @@ This module provides functionality to:
 
 import logging
 from typing import Any, Optional, Union
+
 from sqlalchemy.orm import Session
 
 from app.models import ApplicationSettings
@@ -19,27 +20,27 @@ logger = logging.getLogger(__name__)
 def load_settings_from_db(settings_obj, db_session: Session) -> None:
     """
     Load settings from database and apply them to the settings object.
-    
+
     Database settings take precedence over environment variables and defaults.
     This function should be called after database initialization.
-    
+
     Args:
         settings_obj: The Settings instance to update
         db_session: Database session to use for loading settings
     """
     try:
         db_settings = db_session.query(ApplicationSettings).all()
-        
+
         if not db_settings:
             logger.info("No database settings found, using environment/defaults")
             return
-        
+
         # Apply database settings to the settings object
         updated_count = 0
         for db_setting in db_settings:
             key = db_setting.key
             value = db_setting.value
-            
+
             # Check if the setting exists in the Settings class
             if hasattr(settings_obj, key):
                 # Get the field info to determine the type
@@ -47,17 +48,17 @@ def load_settings_from_db(settings_obj, db_session: Session) -> None:
                 if field_info:
                     # Convert value to the appropriate type
                     converted_value = convert_setting_value(value, field_info.annotation)
-                    
+
                     # Set the attribute
                     setattr(settings_obj, key, converted_value)
                     updated_count += 1
                     logger.debug(f"Applied database setting: {key}")
-        
+
         if updated_count > 0:
             logger.info(f"Loaded {updated_count} settings from database")
         else:
             logger.info("No applicable database settings found")
-            
+
     except Exception as e:
         logger.error(f"Error loading settings from database: {e}")
         # Don't fail application startup if database settings can't be loaded
@@ -67,27 +68,27 @@ def load_settings_from_db(settings_obj, db_session: Session) -> None:
 def convert_setting_value(value: Optional[str], field_type: Any) -> Any:
     """
     Convert a string value from database to the appropriate type.
-    
+
     Args:
         value: String value from database
         field_type: Target type from Pydantic field annotation
-        
+
     Returns:
         Converted value in the appropriate type
     """
     if value is None:
         return None
-    
+
     # Handle Optional types
-    origin = getattr(field_type, '__origin__', None)
+    origin = getattr(field_type, "__origin__", None)
     if origin is Union:
         # Get the non-None type from Union (for Optional)
-        args = getattr(field_type, '__args__', ())
+        args = getattr(field_type, "__args__", ())
         field_type = next((arg for arg in args if arg is not type(None)), str)
-    
+
     # Convert based on type
     if field_type == bool:
-        return value.lower() in ('true', '1', 'yes', 'y', 't')
+        return value.lower() in ("true", "1", "yes", "y", "t")
     elif field_type == int:
         try:
             return int(value)
@@ -100,10 +101,10 @@ def convert_setting_value(value: Optional[str], field_type: Any) -> Any:
         except ValueError:
             logger.warning(f"Failed to convert '{value}' to float, returning 0.0")
             return 0.0
-    elif field_type == list or getattr(field_type, '__origin__', None) == list:
+    elif field_type == list or getattr(field_type, "__origin__", None) == list:
         # Handle list types - assume comma-separated values
         if isinstance(value, str):
-            return [item.strip() for item in value.split(',') if item.strip()]
+            return [item.strip() for item in value.split(",") if item.strip()]
         return value
     else:
         # Default to string
@@ -113,19 +114,19 @@ def convert_setting_value(value: Optional[str], field_type: Any) -> Any:
 def reload_settings_from_db(settings_obj) -> bool:
     """
     Reload settings from database.
-    
+
     This is useful after settings have been updated through the UI.
     Note: Some settings require application restart to take effect.
-    
+
     Args:
         settings_obj: The Settings instance to update
-        
+
     Returns:
         True if reload was successful, False otherwise
     """
     try:
         from app.database import SessionLocal
-        
+
         db = SessionLocal()
         try:
             load_settings_from_db(settings_obj, db)