feat(staff): Restrict staff permissions and add schedule view

- Backend: Restrict staff from accessing resources, customers, services, and tasks APIs
- Frontend: Hide management sidebar links from staff members
- Add StaffSchedule page with vertical timeline view of appointments
- Add StaffHelp page with staff-specific documentation
- Return linked_resource_id and can_edit_schedule in user profile for staff

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

smoothschedule/config/settings/multitenancy.py

@@ -49,6 +49,7 @@ SHARED_APPS = [
     'notifications', # Notification system - shared for platform to notify tenants
     'smoothschedule.public_api', # Public API v1 for third-party integrations
     'smoothschedule.comms_credits', # Communication credits (SMS/calling) - shared for billing
+    'smoothschedule.field_mobile', # Field employee mobile app - shared for location tracking
 ]
 
 # Tenant-specific apps - Each tenant gets isolated data in their own schema