Merge website-branding feature and adjust for compatibility

- Resolved conflicts in models.py, app.py, and template files
- Added branding checks to prevent errors when g.branding is None
- Updated all template references to use conditional branding
- Added BrandingSettings to migrations
- Created branding uploads directory
- Integrated branding with existing comment and task management features

templates/setup_2fa.html

@@ -25,7 +25,7 @@
                 <div class="manual-entry">
                     <h3>Can't scan? Enter this code manually:</h3>
                     <div class="secret-code">{{ secret }}</div>
-                    <p><small>Account: {{ g.user.email }}<br>Issuer: TimeTrack</small></p>
+                    <p><small>Account: {{ g.user.email }}<br>Issuer: {{ g.branding.app_name }}</small></p>
                 </div>
             </div>
         </div>