fix(audit): nettoyage accès, garde-fous build, unification quotas

Semaine 1 — fuites et accès :
- /archive rendu accessible via sidebar (était invisible)
- Suppression pages orphelines : /chat, /graph, /support, test-title-suggestions
- Fixes i18n : search-modal (clé non interpolée), sidebar tooltips, export PDF
- 15 locales mises à jour

Semaine 2 — garde-fous :
- 8 erreurs TS fixees → ignoreBuildErrors: false (build type-safe)
- reactStrictMode: true (dev-only, zero impact prod)
- reserveUsageOrThrow → wrapper deprecie vers reserveAiUsageOrThrow
- auth-guard.ts : requireAuthOrResponse() + requireAdminOrResponse()

Tests 212/212 | Lint 0 erreur | Build OK | tsc 0 erreur

memento-note/auth.config.ts

@@ -23,15 +23,12 @@ export const authConfig = {
                              nextUrl.pathname.startsWith('/settings') ||
                              nextUrl.pathname.startsWith('/lab') ||
                              nextUrl.pathname.startsWith('/agents') ||
-                             nextUrl.pathname.startsWith('/chat') ||
                              nextUrl.pathname.startsWith('/canvas') ||
                              nextUrl.pathname.startsWith('/notebooks') ||
                              nextUrl.pathname.startsWith('/note/') ||
                              nextUrl.pathname.startsWith('/brainstorm') ||
                              nextUrl.pathname.startsWith('/insights') ||
-                             nextUrl.pathname.startsWith('/graph') ||
-                             nextUrl.pathname.startsWith('/revision') ||
-                             nextUrl.pathname.startsWith('/support');
+                             nextUrl.pathname.startsWith('/revision');
       const isAdminPage = nextUrl.pathname.startsWith('/admin');
       const isPublicPage = nextUrl.pathname === '/' ||
                           nextUrl.pathname === '/login' ||