Update staff roles, documentation, and add tenant API

Staff Roles:
- Remove Support Staff default role (now Manager and Staff only)
- Add position field for custom role ordering
- Update StaffRolesSettings with improved permission UI
- Add RolePermissions component for visual permission display

Documentation Updates:
- HelpStaff: Explain two-tier permission system (User Roles + Staff Roles)
- HelpSettingsStaffRoles: Update default roles, add settings access permissions
- HelpComprehensive: Update staff roles section with correct role structure
- HelpCustomers: Add customer creation and onboarding sections
- HelpContracts: Add lifecycle, snapshotting, and signing experience docs
- HelpSettingsAppearance: Update with 20 color palettes and navigation text

Tenant API:
- Add new isolated API at /tenant-api/v1/ for third-party integrations
- Token-based authentication with scope permissions
- Endpoints: business, services, resources, availability, bookings, customers, webhooks

Tests:
- Add test coverage for Celery tasks across modules
- Reorganize schedule view tests for better maintainability

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

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

frontend/src/App.tsx

@@ -829,7 +829,6 @@ const AppContent: React.FC = () => {
             <Route path="/dashboard/help/contracts" element={<HelpContracts />} />
             <Route path="/dashboard/help/automations" element={<HelpAutomations />} />
             <Route path="/dashboard/help/site-builder" element={<HelpSiteBuilder />} />
-            <Route path="/dashboard/help/api" element={<HelpApiOverview />} />
             <Route path="/dashboard/help/api/appointments" element={<HelpApiAppointments />} />
             <Route path="/dashboard/help/api/services" element={<HelpApiServices />} />
             <Route path="/dashboard/help/api/resources" element={<HelpApiResources />} />