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/lib/entitlements.ts

@@ -7,8 +7,13 @@ import {
   parseRedisInt,
   isValidFeature,
 } from './quota-utils';
-
-type SubscriptionTier = 'BASIC' | 'PRO' | 'BUSINESS' | 'ENTERPRISE';
+import {
+  getLimitAsync,
+  getTierFeaturesAsync,
+  invalidateEntitlementCache,
+  TIER_LIMITS,
+  type SubscriptionTier,
+} from './plan-entitlements';
 
 export interface EntitlementResult {
   allowed: boolean;
@@ -70,79 +75,8 @@ export class QuotaExceededError extends Error {
   }
 }
 
-const TIER_LIMITS: Record<SubscriptionTier, Record<string, number | 'unlimited'>> = {
-  BASIC: {
-    semantic_search: 30,
-    auto_tag: 15,
-    auto_title: 5,
-    brainstorm_create: 1,
-    brainstorm_expand: 10,
-    brainstorm_enrich: 20,
-    suggest_charts: 5,
-    ai_flashcard: 5,
-    voice_transcribe: 20,
-  },
-  PRO: {
-    semantic_search: 200,
-    auto_tag: 500,
-    auto_title: 200,
-    reformulate: 50,
-    chat: 50,
-    brainstorm_create: 5,
-    brainstorm_expand: 100,
-    brainstorm_enrich: 200,
-    suggest_charts: 50,
-    slide_generate: 20,
-    excalidraw_generate: 20,
-    ai_flashcard: 100,
-    voice_transcribe: 500,
-  },
-  BUSINESS: {
-    semantic_search: 1000,
-    auto_tag: 1000,
-    auto_title: 1000,
-    reformulate: 500,
-    chat: 500,
-    brainstorm_create: 'unlimited',
-    brainstorm_expand: 500,
-    brainstorm_enrich: 1000,
-    suggest_charts: 200,
-    slide_generate: 100,
-    excalidraw_generate: 100,
-    ai_flashcard: 'unlimited',
-    voice_transcribe: 'unlimited',
-  },
-  ENTERPRISE: {
-    semantic_search: 'unlimited',
-    auto_tag: 'unlimited',
-    auto_title: 'unlimited',
-    reformulate: 'unlimited',
-    chat: 'unlimited',
-    brainstorm_create: 'unlimited',
-    brainstorm_expand: 'unlimited',
-    brainstorm_enrich: 'unlimited',
-    suggest_charts: 'unlimited',
-    slide_generate: 'unlimited',
-    excalidraw_generate: 'unlimited',
-    ai_flashcard: 'unlimited',
-    voice_transcribe: 'unlimited',
-  },
-};
-
 const TTL_SECONDS = 90 * 24 * 60 * 60;
 
-const INCREMENT_LUA = `
-local current = tonumber(redis.call('GET', KEYS[1]) or '0')
-local ttl = tonumber(ARGV[1])
-redis.call('INCRBY', KEYS[1], 1)
-local ttlResult = redis.call('TTL', KEYS[1])
-if ttlResult == -1 then
-  redis.call('EXPIRE', KEYS[1], ttl)
-end
-local newCount = tonumber(redis.call('GET', KEYS[1]))
-return newCount
-`;
-
 const INCREMENT_BY_LUA = `
 local count = tonumber(ARGV[1]) or 1
 local ttl = tonumber(ARGV[2])
@@ -171,14 +105,6 @@ local newCount = tonumber(redis.call('GET', KEYS[1]))
 return newCount
 `;
 
-function getLimit(tier: SubscriptionTier, feature: string): number | undefined {
-  const tierLimits = TIER_LIMITS[tier];
-  const limit = tierLimits?.[feature];
-  if (limit === 'unlimited') return Infinity;
-  if (limit === undefined) return undefined;
-  return limit;
-}
-
 export async function getUserInfo(
   userId: string,
 ): Promise<{ tier: SubscriptionTier; status: string; currentPeriodEnd?: Date }> {
@@ -223,7 +149,7 @@ export async function canUseFeature(
   }
 
   const tier = await getEffectiveTier(userId);
-  const limit = getLimit(tier, feature);
+  const limit = await getLimitAsync(tier, feature);
 
   if (limit === undefined) {
     return {
@@ -300,7 +226,7 @@ export async function reserveUsageOrThrow(
   }
 
   const tier = await getEffectiveTier(userId);
-  const limit = getLimit(tier, feature);
+  const limit = await getLimitAsync(tier, feature);
 
   if (limit === undefined) {
     throw new QuotaExceededError(
@@ -374,8 +300,8 @@ export async function getUserQuotas(
   userId: string,
 ): Promise<Record<string, { remaining: number; limit: number; used: number }>> {
   const tier = await getEffectiveTier(userId);
+  const features = await getTierFeaturesAsync(tier);
   const period = getCurrentPeriodKey();
-  const features = Object.keys(TIER_LIMITS[tier]);
 
   if (features.length === 0) return {};
 
@@ -387,7 +313,7 @@ export async function getUserQuotas(
     const result: Record<string, { remaining: number; limit: number; used: number }> = {};
     for (let i = 0; i < features.length; i++) {
       const feature = features[i];
-      const limit = getLimit(tier, feature) ?? 0;
+      const limit = (await getLimitAsync(tier, feature)) ?? 0;
       const current = parseRedisInt(values[i]);
       result[feature] = {
         remaining: limit === Infinity ? Infinity : Math.max(0, limit - current),
@@ -401,12 +327,17 @@ export async function getUserQuotas(
     console.error('[entitlements] getUserQuotas Redis error:', err);
     const result: Record<string, { remaining: number; limit: number; used: number }> = {};
     for (const feature of features) {
-      const limit = getLimit(tier, feature) ?? 0;
+      const limit = (await getLimitAsync(tier, feature)) ?? 0;
       result[feature] = { remaining: limit, limit, used: 0 };
     }
     return result;
   }
 }
 
-export { TIER_LIMITS, getLimit };
+export { TIER_LIMITS, invalidateEntitlementCache };
 export type { SubscriptionTier };
+
+/** @deprecated Use getLimitAsync — sync helper for tests only */
+export async function getLimit(tier: SubscriptionTier, feature: string): Promise<number | undefined> {
+  return getLimitAsync(tier, feature);
+}