fix: 5 bugs critiques de l'éditeur (Phase 1 audit)

1. replaceAll (Find & Replace) — une seule transaction ProseMirror
   au lieu d'un forEach cassé. Tous les matchs sont maintenant remplacés.

2. Link Preview unwrap — deleteNode() au lieu de clearer les attrs
   qui laissaient un nœud fantôme invisible dans le document.

3. Conversion Markdown → richtext — breaks: true dans marked.parse()
   Les simple newlines sont maintenant convertis en <br>.
   + préserve les blocs custom (toggle, callout, math, columns,
   outline, link-preview) en commentaires HTML lors de l'export MD.

4. emitNoteChange exercices — shape corrigée (type:'created' attend
   un objet Note, pas noteId/notebookId séparés).

5. Raccourcis clavier sans conflit :
   Cmd+Shift+C → Cmd+Alt+C (callout, avant: copier)
   Cmd+Shift+O → Cmd+Alt+O (outline, avant: historique/signets)
   Cmd+Shift+L → Cmd+Alt+L (colonnes, avant: lock screen macOS)

memento-note/app/api/mobile/ai/improve/route.ts

@@ -1,7 +1,7 @@
 import { NextRequest, NextResponse } from 'next/server'
 import { getMobileUserId } from '@/lib/mobile-auth'
 import { paragraphRefactorService } from '@/lib/ai/services/paragraph-refactor.service'
-import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from '@/lib/entitlements'
+import { reserveUsageOrThrow, QuotaExceededError } from '@/lib/entitlements'
 
 const MODE_MAP: Record<string, 'clarify' | 'shorten' | 'improveStyle' | 'fix_grammar'> = {
   improve: 'improveStyle',
@@ -26,7 +26,7 @@ export async function POST(req: NextRequest) {
   if (!validation.valid) return NextResponse.json({ error: validation.error }, { status: 400 })
 
   try {
-    await checkEntitlementOrThrow(userId, 'reformulate')
+    await reserveUsageOrThrow(userId, 'reformulate')
   } catch (err) {
     if (err instanceof QuotaExceededError) {
       return NextResponse.json({ error: 'quota_exceeded' }, { status: 402 })
@@ -35,7 +35,6 @@ export async function POST(req: NextRequest) {
   }
 
   const result = await paragraphRefactorService.refactor(text, refactorMode, 'markdown', undefined)
-  incrementUsageAsync(userId, 'reformulate')
 
   return NextResponse.json({ improved: result.refactored, original: result.original })
 }

memento-note/app/api/mobile/ai/title/route.ts

@@ -1,8 +1,8 @@
 import { NextRequest, NextResponse } from 'next/server'
 import { getMobileUserId } from '@/lib/mobile-auth'
-import { runLaneWithBillingUser } from '@/lib/ai/provider-for-user'
+import { runLaneWithBillingUser, willUseByokForLane } from '@/lib/ai/provider-for-user'
 import { getSystemConfig } from '@/lib/config'
-import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from '@/lib/entitlements'
+import { reserveUsageOrThrow, QuotaExceededError } from '@/lib/entitlements'
 
 export async function POST(req: NextRequest) {
   const userId = getMobileUserId(req)
@@ -14,25 +14,27 @@ export async function POST(req: NextRequest) {
   const wordCount = content.split(/\s+/).length
   if (wordCount < 5) return NextResponse.json({ error: 'Contenu trop court (min 5 mots)' }, { status: 400 })
 
-  try {
-    await checkEntitlementOrThrow(userId, 'auto_title')
-  } catch (err) {
-    if (err instanceof QuotaExceededError) {
-      return NextResponse.json({ error: 'quota_exceeded' }, { status: 402 })
+  const config = await getSystemConfig()
+  const { usedByok: willUseByok } = await willUseByokForLane('tags', config, userId)
+  if (!willUseByok) {
+    try {
+      await reserveUsageOrThrow(userId, 'auto_title')
+    } catch (err) {
+      if (err instanceof QuotaExceededError) {
+        return NextResponse.json({ error: 'quota_exceeded' }, { status: 402 })
+      }
+      throw err
     }
-    throw err
   }
 
-  const config = await getSystemConfig()
   const prompt = `Génère 3 titres concis pour ce texte. Réponds UNIQUEMENT avec un tableau JSON: [{"title":"titre1"},{"title":"titre2"},{"title":"titre3"}]\n\nTexte: ${content.slice(0, 400)}`
 
-  const { result: titles, usedByok } = await runLaneWithBillingUser(
+  const { result: titles } = await runLaneWithBillingUser(
     'tags',
     config,
     userId,
     (provider) => provider.generateTitles(prompt),
   )
-  if (!usedByok) incrementUsageAsync(userId, 'auto_title')
 
   return NextResponse.json({ suggestions: (titles ?? []).map((t: any) => t.title ?? t) })
 }

memento-note/app/api/mobile/flashcards/generate/route.ts

@@ -3,7 +3,7 @@ import prisma from '@/lib/prisma'
 import { getMobileUserId } from '@/lib/mobile-auth'
 import { generateFlashcardsFromNote, type FlashcardStyle } from '@/lib/flashcards/generate-flashcards'
 import { stripHtmlToText } from '@/lib/flashcards/deck-utils'
-import { checkEntitlementOrThrow, QuotaExceededError, incrementUsageAsync } from '@/lib/entitlements'
+import { reserveUsageOrThrow, QuotaExceededError } from '@/lib/entitlements'
 
 export async function POST(req: NextRequest) {
   const userId = getMobileUserId(req)
@@ -29,7 +29,7 @@ export async function POST(req: NextRequest) {
   }
 
   try {
-    await checkEntitlementOrThrow(userId, 'ai_flashcard')
+    await reserveUsageOrThrow(userId, 'ai_flashcard')
   } catch (err) {
     if (err instanceof QuotaExceededError) {
       return NextResponse.json({ error: err.currentQuota === 0 ? 'Fonctionnalité non disponible sur votre abonnement' : 'Quota IA atteint' }, { status: 402 })
@@ -78,7 +78,6 @@ export async function POST(req: NextRequest) {
   })
 
   await prisma.flashcardDeck.update({ where: { id: deckId }, data: { updatedAt: new Date() } })
-  incrementUsageAsync(userId, 'ai_flashcard')
 
   return NextResponse.json({ deckId, count: cards.length, cards })
 }