feat: comprehensive security, performance, UX and deployment audit

Security:
- CORS restricted to explicit methods/headers, configurable via CORS_ORIGINS env
- Auth added to /reports/{rid}/html and /compliance-report endpoints
- Ownership check on report downloads
- Rate limiting on login (10 attempts/5min per IP with threading.Lock)
- Non-root container user (agent via gosu entrypoint)
- Nginx security headers (X-Frame-Options, X-Content-Type-Options, X-XSS-Protection, Referrer-Policy, Permissions-Policy)
- .gitignore and .dockerignore for secret leak prevention
- .env.example with documentation

Performance:
- 16 SQLite indexes on foreign keys and frequently queried columns
- Pagination on chat messages (100), reports (50), audit log (100)
- subprocess.run wrapped in run_in_executor (3 async handlers)
- asyncio.wait_for timeouts on GenAI calls (300s) and Chromium PDF (120s)
- Thread pool reduced to 10 workers
- Code splitting with React.lazy (bundle: 1.3MB -> ~550KB initial)
- React.memo on TreeItem (recursive compartment tree)

Error handling:
- 13 bare except clauses replaced with logged Exception handlers
- Graceful shutdown handler (terminates subprocesses + executor)
- File upload validation (50MB max, extension whitelist per endpoint)
- Health check expanded (version, uptime, db_ok)
- Cache-Control on /api/genai/models (1h)
- Auto-cleanup audit_log > 30 days

Dead code removed:
- DownloadsPage.tsx, StubPage.tsx, MfaPage.tsx (moved to UsersPage)
- Legacy frontend/ directory
- 19 unused i18n keys, dist/ removed from git tracking

UX & i18n:
- 8 alert() calls replaced with styled error states (TerraformPage)
- 50+ hardcoded Portuguese strings localized to i18n (pt/en) across 11 files
- aria-label on all icon-only buttons (Chat, Explorer, Sidebar)
- focus-visible CSS for keyboard navigation
- Responsive grid fix (360px -> 280px for mobile)
- aria-hidden on decorative SVGs

Deployment:
- Docker resource limits (backend 4G, frontend 512M)
- Log rotation (json-file, 10MB x 3)
- Terraform version parameterized via ARG

frontend-react/src/App.tsx

@@ -1,24 +1,34 @@
-import { useEffect } from 'react';
+import { useEffect, lazy, Suspense } from 'react';
 import { Routes, Route, Navigate } from 'react-router-dom';
 import { useAuthStore } from '@/stores/auth';
 import { useAppStore } from '@/stores/app';
 import AppShell from '@/components/layout/AppShell';
-import LoginPage from '@/pages/LoginPage';
-import ChatPage from '@/pages/ChatPage';
-import TerraformPage from '@/pages/TerraformPage';
-import PromptGeneratorPage from '@/pages/PromptGeneratorPage';
-import WorkspacesPage from '@/pages/WorkspacesPage';
-import ExplorerPage from '@/pages/ExplorerPage';
-import ReportsPage from '@/pages/ReportsPage';
-import OciConfigPage from '@/pages/config/OciConfigPage';
-import GenAiConfigPage from '@/pages/config/GenAiConfigPage';
-import McpServersPage from '@/pages/config/McpServersPage';
-import AdbConfigPage from '@/pages/config/AdbConfigPage';
-import EmbeddingsPage from '@/pages/config/EmbeddingsPage';
-import EmbConsultPage from '@/pages/config/EmbConsultPage';
-import UsersPage from '@/pages/admin/UsersPage';
-import MfaPage from '@/pages/admin/MfaPage';
-import AuditPage from '@/pages/admin/AuditPage';
+import { Loader2 } from 'lucide-react';
+
+// Lazy-loaded pages (code splitting)
+const LoginPage = lazy(() => import('@/pages/LoginPage'));
+const ChatPage = lazy(() => import('@/pages/ChatPage'));
+const TerraformPage = lazy(() => import('@/pages/TerraformPage'));
+const PromptGeneratorPage = lazy(() => import('@/pages/PromptGeneratorPage'));
+const WorkspacesPage = lazy(() => import('@/pages/WorkspacesPage'));
+const ExplorerPage = lazy(() => import('@/pages/ExplorerPage'));
+const ReportsPage = lazy(() => import('@/pages/ReportsPage'));
+const OciConfigPage = lazy(() => import('@/pages/config/OciConfigPage'));
+const GenAiConfigPage = lazy(() => import('@/pages/config/GenAiConfigPage'));
+const McpServersPage = lazy(() => import('@/pages/config/McpServersPage'));
+const AdbConfigPage = lazy(() => import('@/pages/config/AdbConfigPage'));
+const EmbeddingsPage = lazy(() => import('@/pages/config/EmbeddingsPage'));
+const EmbConsultPage = lazy(() => import('@/pages/config/EmbConsultPage'));
+const UsersPage = lazy(() => import('@/pages/admin/UsersPage'));
+const AuditPage = lazy(() => import('@/pages/admin/AuditPage'));
+
+function PageLoader() {
+  return (
+    <div className="flex items-center justify-center h-full" style={{ color: 'var(--t4)' }}>
+      <Loader2 size={24} className="animate-spin" />
+    </div>
+  );
+}
 
 export default function App() {
   const checkAuth = useAuthStore((s) => s.checkAuth);
@@ -31,33 +41,33 @@ export default function App() {
     });
   }, [checkAuth, loadData]);
 
-  // Reload data when user changes (login)
   useEffect(() => {
     if (user) loadData();
   }, [user, loadData]);
 
   return (
-    <Routes>
-      <Route path="/login" element={<LoginPage />} />
-      <Route element={<AppShell />}>
-        <Route index element={<Navigate to="/chat" replace />} />
-        <Route path="/chat" element={<ChatPage />} />
-        <Route path="/terraform" element={<TerraformPage />} />
-        <Route path="/terraform/prompt" element={<PromptGeneratorPage />} />
-        <Route path="/terraform/workspaces" element={<WorkspacesPage />} />
-        <Route path="/explorer" element={<ExplorerPage />} />
-        <Route path="/reports" element={<ReportsPage />} />
-        <Route path="/config/oci" element={<OciConfigPage />} />
-        <Route path="/config/genai" element={<GenAiConfigPage />} />
-        <Route path="/config/mcp" element={<McpServersPage />} />
-        <Route path="/config/adb" element={<AdbConfigPage />} />
-        <Route path="/config/embeddings" element={<EmbeddingsPage />} />
-        <Route path="/config/embeddings/consult" element={<EmbConsultPage />} />
-        <Route path="/admin/users" element={<UsersPage />} />
-        <Route path="/admin/mfa" element={<MfaPage />} />
-        <Route path="/admin/audit" element={<AuditPage />} />
-      </Route>
-      <Route path="*" element={<Navigate to="/chat" replace />} />
-    </Routes>
+    <Suspense fallback={<PageLoader />}>
+      <Routes>
+        <Route path="/login" element={<LoginPage />} />
+        <Route element={<AppShell />}>
+          <Route index element={<Navigate to="/chat" replace />} />
+          <Route path="/chat" element={<ChatPage />} />
+          <Route path="/terraform" element={<TerraformPage />} />
+          <Route path="/terraform/prompt" element={<PromptGeneratorPage />} />
+          <Route path="/terraform/workspaces" element={<WorkspacesPage />} />
+          <Route path="/explorer" element={<ExplorerPage />} />
+          <Route path="/reports" element={<ReportsPage />} />
+          <Route path="/config/oci" element={<OciConfigPage />} />
+          <Route path="/config/genai" element={<GenAiConfigPage />} />
+          <Route path="/config/mcp" element={<McpServersPage />} />
+          <Route path="/config/adb" element={<AdbConfigPage />} />
+          <Route path="/config/embeddings" element={<EmbeddingsPage />} />
+          <Route path="/config/embeddings/consult" element={<EmbConsultPage />} />
+          <Route path="/admin/users" element={<UsersPage />} />
+          <Route path="/admin/audit" element={<AuditPage />} />
+        </Route>
+        <Route path="*" element={<Navigate to="/chat" replace />} />
+      </Routes>
+    </Suspense>
   );
 }