feat(settings): Settings page with email, webhooks, notifications, profile [FASE-8]

- SystemConfig model + migration b033 for runtime key-value config
- GET/PATCH /system/email-config + POST /system/email-test (admin only)
- email_service reads SMTP config from DB (overrides .env)
- Webhooks now accessible to red_lead/blue_lead + admin
- GET /users/me already existed; /users/me/preferences already working
- SettingsPage with 4 role-aware tabs:
  * Profile & Jira: jira_account_id, user info
  * Notifications: role-specific email/in-app toggles (12 prefs)
  * Webhooks: full CRUD + test ping (leads + admin)
  * Email/SMTP: enable toggle, server config, test email (admin only)
- Added /settings route (all authenticated users)
- Settings link added to Sidebar

frontend/src/App.tsx

@@ -28,6 +28,7 @@ const ThreatActorDetailPage = React.lazy(() => import("./pages/ThreatActorDetail
 const CampaignsPage = React.lazy(() => import("./pages/CampaignsPage"));
 const CampaignDetailPage = React.lazy(() => import("./pages/CampaignDetailPage"));
 const ComparisonPage = React.lazy(() => import("./pages/ComparisonPage"));
+const SettingsPage = React.lazy(() => import("./pages/SettingsPage"));
 
 export default function App() {
   return (
@@ -92,6 +93,9 @@ export default function App() {
         {/* ── Reports ──────────────────────────────────────────── */}
         <Route path="/reports" element={<Suspense fallback={<LoadingSpinner text="Loading…" />}><ReportsPage /></Suspense>} />
 
+        {/* ── Settings (all authenticated users) ───────────────── */}
+        <Route path="/settings" element={<Suspense fallback={<LoadingSpinner text="Loading…" />}><SettingsPage /></Suspense>} />
+
         {/* ── System (admin only) ──────────────────────────────── */}
         <Route
           path="/system"