Add platform email templates, staff invitations, and quota tracking

- Add PlatformEmailTemplate model and API for superuser-managed email templates
- Add PlatformStaffInvitation model with email sending via Celery tasks
- Add platform staff invite page and acceptance flow with auto-login
- Add quota tracking models (DailyAppointmentUsage, DailyAPIUsage, StorageUsage)
- Add quota status API endpoints and frontend banners
- Add storage usage service for tenant media tracking
- Fix platform user deletion with raw SQL to handle multi-tenant FK constraints
- Update EditPlatformUserModal with archive/delete buttons
- Update PlatformSidebar with email templates link for superusers
- Configure console email backend and Celery eager mode for local development

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

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

frontend/src/App.tsx

@@ -66,10 +66,12 @@ const PlatformStaff = React.lazy(() => import('./pages/platform/PlatformStaff'))
 const PlatformSettings = React.lazy(() => import('./pages/platform/PlatformSettings'));
 const BillingManagement = React.lazy(() => import('./pages/platform/BillingManagement'));
 const PlatformStaffEmail = React.lazy(() => import('./pages/platform/PlatformStaffEmail'));
+const PlatformEmailTemplates = React.lazy(() => import('./pages/platform/PlatformEmailTemplates'));
 const ProfileSettings = React.lazy(() => import('./pages/ProfileSettings'));
 const VerifyEmail = React.lazy(() => import('./pages/VerifyEmail'));
 const EmailVerificationRequired = React.lazy(() => import('./pages/EmailVerificationRequired'));
 const AcceptInvitePage = React.lazy(() => import('./pages/AcceptInvitePage'));
+const PlatformStaffInvitePage = React.lazy(() => import('./pages/platform/PlatformStaffInvitePage'));
 const TenantOnboardPage = React.lazy(() => import('./pages/TenantOnboardPage'));
 const TenantLandingPage = React.lazy(() => import('./pages/TenantLandingPage'));
 const Tickets = React.lazy(() => import('./pages/Tickets')); // Import Tickets page
@@ -375,6 +377,7 @@ const AppContent: React.FC = () => {
           <Route path="/verify-email" element={<VerifyEmail />} />
           <Route path="/accept-invite" element={<AcceptInvitePage />} />
           <Route path="/accept-invite/:token" element={<AcceptInvitePage />} />
+          <Route path="/platform-staff-invite" element={<PlatformStaffInvitePage />} />
           <Route path="/tenant-onboard" element={<TenantOnboardPage />} />
           <Route path="/sign/:token" element={<ContractSigning />} />
           <Route path="*" element={<Navigate to="/" replace />} />
@@ -411,6 +414,7 @@ const AppContent: React.FC = () => {
             <Route path="/verify-email" element={<VerifyEmail />} />
             <Route path="/accept-invite" element={<AcceptInvitePage />} />
             <Route path="/accept-invite/:token" element={<AcceptInvitePage />} />
+            <Route path="/platform-staff-invite" element={<PlatformStaffInvitePage />} />
             <Route path="/tenant-onboard" element={<TenantOnboardPage />} />
             <Route path="/sign/:token" element={<ContractSigning />} />
             <Route path="*" element={<Navigate to="/" replace />} />
@@ -419,10 +423,10 @@ const AppContent: React.FC = () => {
       );
     }
 
-    // For platform subdomain, only /platform/login exists - everything else renders nothing
+    // For platform subdomain, only specific paths exist - everything else renders nothing
     if (isPlatformSubdomain) {
       const path = window.location.pathname;
-      const allowedPaths = ['/platform/login', '/mfa-verify', '/verify-email'];
+      const allowedPaths = ['/platform/login', '/mfa-verify', '/verify-email', '/platform-staff-invite'];
 
       // If not an allowed path, render nothing
       if (!allowedPaths.includes(path)) {
@@ -435,6 +439,7 @@ const AppContent: React.FC = () => {
             <Route path="/platform/login" element={<PlatformLoginPage />} />
             <Route path="/mfa-verify" element={<MFAVerifyPage />} />
             <Route path="/verify-email" element={<VerifyEmail />} />
+            <Route path="/platform-staff-invite" element={<PlatformStaffInvitePage />} />
           </Routes>
         </Suspense>
       );
@@ -460,6 +465,7 @@ const AppContent: React.FC = () => {
           <Route path="/verify-email" element={<VerifyEmail />} />
           <Route path="/accept-invite" element={<AcceptInvitePage />} />
           <Route path="/accept-invite/:token" element={<AcceptInvitePage />} />
+          <Route path="/platform-staff-invite" element={<PlatformStaffInvitePage />} />
           <Route path="/tenant-onboard" element={<TenantOnboardPage />} />
           <Route path="/sign/:token" element={<ContractSigning />} />
           <Route path="*" element={<Navigate to="/" replace />} />
@@ -599,6 +605,7 @@ const AppContent: React.FC = () => {
               <>
                 <Route path="/platform/settings" element={<PlatformSettings />} />
                 <Route path="/platform/billing" element={<BillingManagement />} />
+                <Route path="/platform/email-templates" element={<PlatformEmailTemplates />} />
               </>
             )}
             <Route path="/platform/profile" element={<ProfileSettings />} />