Phase 3: UI redesign (Gitea-issues aesthetic)

Top-nav Layout replaces side-nav: brand, primary nav, global search
(debounced /search), notifications bell (Popover + unread badge),
user avatar DropdownMenu. Mobile hamburger collapse.

New pages:
- /dashboard: analytics home (open-by-severity, age buckets, queue
  load, median resolution)
- /tickets: Gitea-style list with status tabs, severity/assignee/CTI
  filters, server pagination (25/page), multi-select bulk bar
  (reassign/close/severity), saved views CRUD
- /notifications: full list with mark-all-read
- /settings: profile, notification prefs grid, API key (SERVICE role)
- /admin/webhooks: CRUD + rotate-secret + active toggle,
  reveal-once secret dialog

TicketDetail: inline Popover editing for Status/Severity/Assignee
(replaces modal chain), AlertDialog delete confirmation, comment
draft autosave to localStorage per ticket.

Admin Users: window.confirm swapped for AlertDialog on delete +
rotate API key with toast feedback.

React Query hooks added for paged tickets, bulk actions,
notifications, webhooks, saved views, analytics, notification prefs.
ThemeProvider wired (v1.0 ships dark-only; toggle deferred).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

client/src/main.tsx

@@ -2,13 +2,18 @@ import { StrictMode } from 'react';
 import { createRoot } from 'react-dom/client';
 import { QueryClientProvider } from '@tanstack/react-query';
 import { queryClient } from './api/queryClient';
+import { ThemeProvider } from './contexts/ThemeContext';
+import { Toaster } from '@/components/ui/sonner';
 import './index.css';
 import App from './App';
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>
-    <QueryClientProvider client={queryClient}>
-      <App />
-    </QueryClientProvider>
+    <ThemeProvider>
+      <QueryClientProvider client={queryClient}>
+        <App />
+        <Toaster />
+      </QueryClientProvider>
+    </ThemeProvider>
   </StrictMode>,
 );