feat: add Ressourcen timeline view with group ordering (alpha.14)

- New timeline page showing all groups and active events in parallel
- Group order API endpoints with persistence (GET/POST /api/groups/order)
- Customizable group ordering with visual controls
- Fix CSS and TypeScript lint errors
- Update documentation and bump version to 2026.1.0-alpha.14

server/init_defaults.py

@@ -68,6 +68,7 @@ with engine.connect() as conn:
             ('holiday_banner_enabled', 'true', 'Ferienstatus-Banner auf Dashboard anzeigen'),
             ('organization_name', '', 'Name der Organisation (wird im Header angezeigt)'),
             ('refresh_seconds', '0', 'Scheduler Republish-Intervall (Sekunden; 0 deaktiviert)'),
+            ('group_order', '[]', 'Benutzerdefinierte Reihenfolge der Raumgruppen (JSON-Array mit Group-IDs)'),
         ]
     
         for key, value, description in default_settings: