feat: Tier 1 & 2 — Daily Note, Voice, Flashcard quota, Readwise, Calendar, Agent Gallery

Tier 1:
- BASIC tier: chat (10/mo) + reformulate (10/mo) désormais accessibles
- Nouveaux quotas: ai_flashcard + voice_transcribe dans tous les tiers
- /api/notes/daily : note du jour auto-créée (find or create)
- Bouton Note du Jour dans la sidebar (CalendarDays)
- Voice-to-Text dans l'éditeur (Web Speech API, bouton Mic toolbar)
- Flashcard generation → quota ai_flashcard (au lieu de reformulate)

Tier 2:
- Intégration Readwise: GET/POST/DELETE /api/integrations/readwise
- Intégration Google Calendar: OAuth flow + today's events + meeting notes
- /api/integrations/calendar + /callback
- Page /settings/integrations avec cards Calendar + Readwise
- SettingsNav: onglet Intégrations
- AgentTemplates: catégories + 4 nouveaux templates (Digest/Recap/AutoTagger/Synthesis)

Schema:
- UserAISettings.integrationTokens Json? (migration 20260529160000)
- prisma generate + migrate deploy appliqués

Fix:
- SpeechRecognition types (triple-slash @types/dom-speech-recognition)
- Notebook.create: suppression champ 'description' inexistant

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

memento-note/app/api/integrations/calendar/callback/route.ts

@@ -0,0 +1,69 @@
+/**
+ * GET /api/integrations/calendar/callback
+ * Google OAuth callback — exchanges code for tokens and persists them.
+ */
+
+import { NextRequest, NextResponse } from 'next/server'
+import prisma from '@/lib/prisma'
+
+const GOOGLE_TOKEN_URL = 'https://oauth2.googleapis.com/token'
+
+export async function GET(req: NextRequest) {
+  const url = new URL(req.url)
+  const code = url.searchParams.get('code')
+  const userId = url.searchParams.get('state')
+  const error = url.searchParams.get('error')
+
+  if (error || !code || !userId) {
+    return NextResponse.redirect(
+      `${url.origin}/settings/integrations?error=calendar_auth_failed`,
+    )
+  }
+
+  const clientId = process.env.GOOGLE_CALENDAR_CLIENT_ID || process.env.AUTH_GOOGLE_ID || ''
+  const clientSecret = process.env.GOOGLE_CALENDAR_CLIENT_SECRET || process.env.AUTH_GOOGLE_SECRET || ''
+  const redirectUri = `${url.origin}/api/integrations/calendar/callback`
+
+  const tokenRes = await fetch(GOOGLE_TOKEN_URL, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
+    body: new URLSearchParams({
+      client_id: clientId,
+      client_secret: clientSecret,
+      code,
+      redirect_uri: redirectUri,
+      grant_type: 'authorization_code',
+    }),
+  })
+
+  const tokenData = await tokenRes.json()
+
+  if (!tokenData.access_token) {
+    return NextResponse.redirect(
+      `${url.origin}/settings/integrations?error=calendar_token_failed`,
+    )
+  }
+
+  // Persist tokens in UserAISettings.integrationTokens
+  const aiSettings = await prisma.userAISettings.findUnique({
+    where: { userId },
+    select: { integrationTokens: true },
+  })
+  const meta =
+    typeof aiSettings?.integrationTokens === 'string'
+      ? JSON.parse(aiSettings.integrationTokens)
+      : (aiSettings?.integrationTokens as Record<string, unknown> | null) ?? {}
+
+  meta.calendarAccessToken = tokenData.access_token
+  if (tokenData.refresh_token) {
+    meta.calendarRefreshToken = tokenData.refresh_token
+  }
+
+  await prisma.userAISettings.upsert({
+    where: { userId },
+    update: { integrationTokens: JSON.stringify(meta) },
+    create: { userId, integrationTokens: JSON.stringify(meta) },
+  })
+
+  return NextResponse.redirect(`${url.origin}/settings/integrations?connected=calendar`)
+}