fix(quotas): unifier le décompte IA (BYOK, rollback) et combler les fuites

Centralise la réserve via ai-quota, corrige admin unavailable (-1), brancher les routes sans quota et le host-pays brainstorm, avec usage-meter élargi, noms de clusters, MCP et ajustements dashboard/insights.

Co-authored-by: Cursor <cursoragent@cursor.com>

memento-note/lib/ai/services/clustering.service.ts

@@ -15,6 +15,7 @@ import prisma from '@/lib/prisma'
 import { embeddingService } from './embedding.service'
 import { getChatProvider } from '@/lib/ai/factory'
 import { getSystemConfig } from '@/lib/config'
+import { withAiQuota } from '@/lib/ai-quota'
 import { upsertNoteEmbedding } from '@/lib/embeddings'
 
 export interface ClusterResult {
@@ -570,22 +571,36 @@ export class ClusteringService {
 
   /**
    * Get the N most central notes from a cluster for naming purposes.
+   * Falls back to any members ranked by membershipScore if none marked central.
    */
   async getCentralNotes(clusterId: number, userId: string, n: number = 5): Promise<Array<{ noteId: string; title: string | null; content: string }>> {
-    const result = await prisma.$queryRawUnsafe<Array<{ noteId: string; title: string | null; content: string }>>(
-      `SELECT DISTINCT n.id AS "noteId", n.title, n.content
+    const central = await prisma.$queryRawUnsafe<Array<{ noteId: string; title: string | null; content: string }>>(
+      `SELECT n.id AS "noteId", n.title, n.content
        FROM "ClusterMember" cm
        INNER JOIN "Note" n ON n.id = cm."noteId"
        WHERE cm."clusterId" = $1
          AND cm."userId" = $2
          AND cm."isCentral" = true
+       ORDER BY cm."membershipScore" DESC
        LIMIT $3`,
       clusterId,
       userId,
       n
     )
+    if (central.length > 0) return central
 
-    return result
+    return prisma.$queryRawUnsafe<Array<{ noteId: string; title: string | null; content: string }>>(
+      `SELECT n.id AS "noteId", n.title, n.content
+       FROM "ClusterMember" cm
+       INNER JOIN "Note" n ON n.id = cm."noteId"
+       WHERE cm."clusterId" = $1
+         AND cm."userId" = $2
+       ORDER BY cm."membershipScore" DESC
+       LIMIT $3`,
+      clusterId,
+      userId,
+      n
+    )
   }
 
   /**
@@ -628,38 +643,156 @@ export class ClusteringService {
     })
   }
 
+  isPlaceholderClusterName(name: string | null | undefined): boolean {
+    if (!name || !name.trim()) return true
+    return /^cluster\s*\d+$/i.test(name.trim())
+  }
+
+  private heuristicNameFromNotes(
+    notes: Array<{ title: string | null; content: string }>,
+    clusterId: number
+  ): string {
+    for (const note of notes) {
+      const title = note.title?.trim()
+      if (title && title.length >= 3) {
+        return title.length > 48 ? `${title.slice(0, 45)}…` : title
+      }
+    }
+    const snippet = notes[0]?.content?.replace(/<[^>]+>/g, ' ').trim()
+    if (snippet && snippet.length >= 3) {
+      return snippet.length > 48 ? `${snippet.slice(0, 45)}…` : snippet
+    }
+    return `Thème ${clusterId}`
+  }
+
   /**
-   * Generate a name for a cluster using the LLM.
-   * Analyzes the 5 most central notes to extract a common theme.
+   * Name a cluster from in-memory notes (does NOT require ClusterMember rows in DB).
+   * Critical: POST /api/clusters used to call generateClusterName *before* save → empty centrals → "Cluster 15".
+   */
+  async generateClusterNameFromNotes(
+    notes: Array<{ title: string | null; content: string }>,
+    clusterId: number,
+    userId?: string,
+  ): Promise<string> {
+    if (notes.length === 0) {
+      return this.heuristicNameFromNotes(notes, clusterId)
+    }
+
+    const notesText = notes
+      .slice(0, 5)
+      .map((note, i) => `${i + 1}. "${note.title || 'Untitled'}" - ${note.content.replace(/<[^>]+>/g, ' ').slice(0, 100)}...`)
+      .join('\n')
+
+    const systemPrompt =
+      "Vous êtes un assistant d'analyse sémantique. Analysez les notes fournies et dégagez un thème commun clair, élégant et évocateur (2 à 6 mots), dans la langue principale des notes. Ne donnez QUE le titre thématique final, sans ponctuation finale, sans guillemets, sans explication. N'utilisez JAMAIS le format « Cluster 12 »."
+
+    const userPrompt = `Voici des notes du même groupe thématique. Quel est leur thème commun ?\n\n${notesText}\n\nThème :`
+
+    try {
+      const runLlm = async () => {
+        const config = await getSystemConfig()
+        const provider = getChatProvider(config)
+        const response = await provider.chat(
+          [{ role: 'user', content: userPrompt }],
+          systemPrompt,
+        )
+        return response.text.trim().replace(/^["«]|["»]$/g, '').slice(0, 50)
+      }
+
+      const named = userId
+        ? await withAiQuota(userId, 'reformulate', runLlm, { lane: 'chat' })
+        : await runLlm()
+      if (this.isPlaceholderClusterName(named)) {
+        return this.heuristicNameFromNotes(notes, clusterId)
+      }
+      return named || this.heuristicNameFromNotes(notes, clusterId)
+    } catch {
+      return this.heuristicNameFromNotes(notes, clusterId)
+    }
+  }
+
+  /**
+   * Generate a name for a cluster using the LLM (after members are saved).
    */
   async generateClusterName(clusterId: number, userId: string): Promise<string> {
     const centralNotes = await this.getCentralNotes(clusterId, userId, 5)
+    return this.generateClusterNameFromNotes(centralNotes, clusterId, userId)
+  }
 
-    if (centralNotes.length === 0) {
-      return `Cluster ${clusterId}`
+  displayName(name: string | null | undefined, clusterId: number): string {
+    if (this.isPlaceholderClusterName(name)) return `Thème ${clusterId}`
+    return name!.trim()
+  }
+
+  /**
+   * Name clusters from in-memory results (before or without depending on DB members).
+   * Prefer central notes when available.
+   */
+  async nameClustersFromResults(
+    userId: string,
+    results: { clusters: ClusterResult[]; clusteredNotes: ClusteredNote[] }
+  ): Promise<void> {
+    const allNoteIds = [...new Set(results.clusteredNotes.map(n => n.noteId))]
+    const notes = allNoteIds.length
+      ? await prisma.note.findMany({
+          where: { id: { in: allNoteIds }, userId },
+          select: { id: true, title: true, content: true },
+        })
+      : []
+    const byId = new Map(notes.map(n => [n.id, n]))
+
+    for (const cluster of results.clusters) {
+      const members = results.clusteredNotes.filter(n => n.clusterId === cluster.clusterId)
+      const preferred = members.filter(n => n.isCentral)
+      const ordered = (preferred.length > 0 ? preferred : members)
+        .sort((a, b) => b.membershipScore - a.membershipScore)
+        .slice(0, 5)
+      const notePayload = ordered
+        .map(m => byId.get(m.noteId))
+        .filter((n): n is { id: string; title: string | null; content: string } => Boolean(n))
+        .map(n => ({ title: n.title, content: n.content }))
+
+      cluster.name = await this.generateClusterNameFromNotes(notePayload, cluster.clusterId, userId)
     }
+  }
 
-    const notesText = centralNotes
-      .map((note, i) => `${i + 1}. "${note.title || 'Untitled'}" - ${note.content.slice(0, 100)}...`)
-      .join('\n')
-
-    const systemPrompt = "Vous êtes un assistant d'analyse sémantique. Analysez les notes fournies et dégagez un thème commun clair, élégant et évocateur (2 à 4 mots maximum), écrit en français (ou dans la langue principale des notes). Ne donnez QUE le titre thématique final, sans ponctuation, sans guillemets, et sans aucune explication."
-
-    const userPrompt = `Voici 5 notes centrales appartenant au même groupe thématique. Quel est leur thème commun ?\n\n${notesText}\n\nThème :`
-
-    try {
-      const config = await getSystemConfig()
-      const provider = getChatProvider(config)
-      const response = await provider.chat(
-        [{ role: 'user', content: userPrompt }],
-        systemPrompt
-      )
-      return response.text.trim().slice(0, 50)
-    } catch {
-      return `Cluster ${clusterId}`
+  /**
+   * Rename clusters that still have null / "Cluster N" placeholders.
+   * Defaults to fast heuristic titles (central note titles) — no LLM on page load.
+   * Pass useAi: true from cron/admin if needed; normal POST already names via nameClustersFromResults.
+   */
+  async ensureClusterNames(userId: string, options?: { useAi?: boolean }): Promise<void> {
+    const clusters = await prisma.noteCluster.findMany({
+      where: { userId },
+      select: { clusterId: true, name: true },
+    })
+    for (const cluster of clusters) {
+      if (!this.isPlaceholderClusterName(cluster.name)) continue
+      const name = options?.useAi
+        ? await this.generateClusterName(cluster.clusterId, userId)
+        : this.heuristicNameFromNotes(
+            await this.getCentralNotes(cluster.clusterId, userId, 5),
+            cluster.clusterId
+          )
+      await prisma.noteCluster.updateMany({
+        where: { userId, clusterId: cluster.clusterId },
+        data: { name },
+      })
     }
   }
 
+  /**
+   * Current clusterId → human name map (never "Cluster N").
+   */
+  async getClusterNameMap(userId: string): Promise<Map<number, string>> {
+    await this.ensureClusterNames(userId)
+    const clusters = await prisma.noteCluster.findMany({
+      where: { userId },
+      select: { clusterId: true, name: true },
+    })
+    return new Map(clusters.map(c => [c.clusterId, this.displayName(c.name, c.clusterId)]))
+  }
+
   /**
    * Check if recalculation is needed based on data change percentage.
    */
@@ -723,7 +856,7 @@ export class ClusteringService {
       result.push({
         clusterId: cluster.clusterId,
         noteIds: members.map(m => m.noteId),
-        name: cluster.name || undefined
+        name: this.displayName(cluster.name, cluster.clusterId),
       })
     }