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/app/(main)/insights/page.tsx

@@ -19,7 +19,6 @@ import {
   ChevronRight,
   ChevronDown,
   Database,
-  ArrowRight,
   Menu,
   Network,
   List,
@@ -28,7 +27,6 @@ import {
   X,
 } from 'lucide-react'
 import { toast } from 'sonner'
-import Link from 'next/link'
 import { useNotePeek, NotePeekPanel } from '@/components/note-peek'
 import { createNote } from '@/app/actions/notes'
 import { emitNoteChange } from '@/lib/note-change-sync'
@@ -455,9 +453,6 @@ export default function InsightsPage() {
           </p>
           <div className="flex items-center gap-1.5 mt-1.5 text-[10px] text-concrete">
             <span>{t('insightsView.semanticGraphLegend')}</span>
-            <Link href="/graph" className="inline-flex items-center gap-0.5 text-ochre hover:underline font-medium">
-              {t('insightsView.openGraphMap')} <ArrowRight size={9} />
-            </Link>
           </div>
           </div>
         </div>