Consolidate white_label to remove_branding and add embed widget

- Rename white_label feature to remove_branding across frontend/backend
- Update billing catalog, plan features, and permission checks
- Add dark mode support to Recharts tooltips with useDarkMode hook
- Create embeddable booking widget with EmbedBooking page
- Add EmbedWidgetSettings for generating embed code
- Fix Appearance settings page permission check
- Update test files for new feature naming
- Add notes field to User model

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

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

frontend/src/App.tsx

@@ -134,6 +134,10 @@ const BillingSettings = React.lazy(() => import('./pages/settings/BillingSetting
 const QuotaSettings = React.lazy(() => import('./pages/settings/QuotaSettings'));
 const BusinessHoursSettings = React.lazy(() => import('./pages/settings/BusinessHoursSettings'));
 const StaffRolesSettings = React.lazy(() => import('./pages/settings/StaffRolesSettings'));
+const EmbedWidgetSettings = React.lazy(() => import('./pages/settings/EmbedWidgetSettings'));
+
+// Embed pages
+const EmbedBooking = React.lazy(() => import('./pages/EmbedBooking'));
 
 import { Toaster } from 'react-hot-toast'; // Import Toaster for notifications
 
@@ -358,6 +362,7 @@ const AppContent: React.FC = () => {
           <Routes>
             <Route path="/" element={<PublicPage />} />
             <Route path="/book" element={<BookingFlow />} />
+            <Route path="/embed" element={<EmbedBooking />} />
             <Route path="/login" element={<LoginPage />} />
             <Route path="/mfa-verify" element={<MFAVerifyPage />} />
             <Route path="/oauth/callback/:provider" element={<OAuthCallback />} />
@@ -688,6 +693,7 @@ const AppContent: React.FC = () => {
           {/* Public routes outside BusinessLayout */}
           <Route path="/" element={<PublicPage />} />
           <Route path="/book" element={<BookingFlow />} />
+          <Route path="/embed" element={<EmbedBooking />} />
           <Route path="/login" element={<LoginPage />} />
           <Route path="/sign/:token" element={<ContractSigning />} />
 
@@ -953,6 +959,7 @@ const AppContent: React.FC = () => {
                 <Route path="business-hours" element={<BusinessHoursSettings />} />
                 <Route path="email-templates" element={<SystemEmailTemplates />} />
                 <Route path="custom-domains" element={<CustomDomainsSettings />} />
+                <Route path="embed-widget" element={<EmbedWidgetSettings />} />
                 <Route path="api" element={<ApiSettings />} />
                 <Route path="staff-roles" element={<StaffRolesSettings />} />
                 <Route path="authentication" element={<AuthenticationSettings />} />