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/wizard.py

@@ -2,21 +2,16 @@
 Setup wizard views for initial system configuration.
 """
 
-import os
 import logging
 import secrets
-from fastapi import Request, Depends, Form
+
+from fastapi import Depends, Form, Request
 from fastapi.responses import RedirectResponse
 from sqlalchemy.orm import Session
 
-from app.views.base import APIRouter, templates, get_db
-from app.utils.setup_wizard import (
-    is_setup_required,
-    get_required_settings,
-    get_wizard_steps,
-    get_missing_required_settings
-)
 from app.utils.settings_service import save_setting_to_db
+from app.utils.setup_wizard import get_wizard_steps
+from app.views.base import APIRouter, get_db, templates
 
 logger = logging.getLogger(__name__)
 router = APIRouter()
@@ -26,26 +21,26 @@ router = APIRouter()
 async def setup_wizard(request: Request, step: int = 1):
     """
     Setup wizard for first-time configuration.
-    
+
     This wizard guides users through configuring essential settings
     needed for the system to operate properly.
     """
     # Get wizard steps
     wizard_steps = get_wizard_steps()
     max_step = max(wizard_steps.keys())
-    
+
     # Validate step number
     if step < 1:
         step = 1
     elif step > max_step:
         step = max_step
-    
+
     # Get settings for current step
     current_settings = wizard_steps.get(step, [])
-    
+
     # Get step category (all settings in a step should have same category)
     step_category = current_settings[0].get("wizard_category", "Configuration") if current_settings else "Configuration"
-    
+
     return templates.TemplateResponse(
         "setup_wizard.html",
         {
@@ -54,59 +49,55 @@ async def setup_wizard(request: Request, step: int = 1):
             "max_step": max_step,
             "settings": current_settings,
             "step_category": step_category,
-            "progress_percent": int((step / max_step) * 100)
-        }
+            "progress_percent": int((step / max_step) * 100),
+        },
     )
 
 
 @router.post("/setup")
-async def setup_wizard_save(
-    request: Request,
-    step: int = Form(...),
-    db: Session = Depends(get_db)
-):
+async def setup_wizard_save(request: Request, step: int = Form(...), db: Session = Depends(get_db)):
     """
     Save settings from the current wizard step.
     """
     try:
         # Get form data
         form_data = await request.form()
-        
+
         # Get settings for current step
         wizard_steps = get_wizard_steps()
         current_settings = wizard_steps.get(step, [])
-        
+
         # Save each setting from the form
         saved_count = 0
         for setting in current_settings:
             key = setting["key"]
             value = form_data.get(key)
-            
+
             # Skip empty values unless it's explicitly allowed
             if value and value.strip():
                 # Auto-generate session_secret if needed
                 if key == "session_secret" and value == "auto-generate":
                     value = secrets.token_hex(32)
                     logger.info("Auto-generated session secret")
-                
+
                 # Save to database
                 if save_setting_to_db(db, key, value):
                     saved_count += 1
                     logger.info(f"Setup wizard: Saved {key}")
-        
+
         logger.info(f"Setup wizard step {step}: Saved {saved_count} settings")
-        
+
         # Determine next step
         max_step = max(wizard_steps.keys())
         next_step = step + 1
-        
+
         if next_step > max_step:
             # Setup complete, redirect to home
             return RedirectResponse(url="/?setup=complete", status_code=303)
         else:
             # Go to next step
             return RedirectResponse(url=f"/setup?step={next_step}", status_code=303)
-            
+
     except Exception as e:
         logger.error(f"Error saving wizard settings: {e}")
         return RedirectResponse(url=f"/setup?step={step}&error=save_failed", status_code=303)
@@ -116,7 +107,7 @@ async def setup_wizard_save(
 async def setup_wizard_skip(request: Request):
     """
     Skip the setup wizard (for advanced users).
-    
+
     Creates a marker to indicate setup was skipped.
     """
     try: