Add Site Builder help docs and fix FloatingHelpButton paths

- Add HelpSiteBuilder.tsx with comprehensive documentation for the
  drag-and-drop page editor (components, publishing, settings)
- Fix FloatingHelpButton to use /dashboard/help/* paths on tenant sites
- Update HelpComprehensive and HelpAutomations to rename plugins to automations
- Add site-crawler utility with cross-subdomain redirect detection

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

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

frontend/src/App.tsx

@@ -91,6 +91,7 @@ const HelpMessages = React.lazy(() => import('./pages/help/HelpMessages'));
 const HelpPayments = React.lazy(() => import('./pages/help/HelpPayments'));
 const HelpContracts = React.lazy(() => import('./pages/help/HelpContracts'));
 const HelpAutomations = React.lazy(() => import('./pages/help/HelpAutomations'));
+const HelpSiteBuilder = React.lazy(() => import('./pages/help/HelpSiteBuilder'));
 const HelpSettingsGeneral = React.lazy(() => import('./pages/help/HelpSettingsGeneral'));
 const HelpSettingsResourceTypes = React.lazy(() => import('./pages/help/HelpSettingsResourceTypes'));
 const HelpSettingsBooking = React.lazy(() => import('./pages/help/HelpSettingsBooking'));
@@ -760,6 +761,7 @@ const AppContent: React.FC = () => {
             <Route path="/dashboard/help/payments" element={<HelpPayments />} />
             <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/settings/general" element={<HelpSettingsGeneral />} />
             <Route path="/dashboard/help/settings/resource-types" element={<HelpSettingsResourceTypes />} />
             <Route path="/dashboard/help/settings/booking" element={<HelpSettingsBooking />} />