feat(db): extraction des embeddings + mode WAL + config DB provider-agnostic

- Ajout de la table de relation 1-1 NoteEmbedding pour alléger Model Note
- Refactor complet des actions IA sémantique et Memory Echo pour utiliser la jointure
- Migration propre des 85 embeddings locaux existants
- Ajout PRAGMA journal_mode=WAL pour la concurrence au sein de lib/prisma
- Ajout npm run db:switch pour configuration auto SQLite / PostgreSQL
- Fix du compilateur Turbopack et Next-PWA

keep-notes/scripts/migrate-embeddings.ts

@@ -0,0 +1,61 @@
+// scripts/migrate-embeddings.ts
+const { PrismaClient } = require('../prisma/client-generated')
+
+const prisma = new PrismaClient({
+  datasources: {
+    db: {
+      url: process.env.DATABASE_URL || "file:../prisma/dev.db"
+    }
+  }
+})
+
+async function main() {
+  console.log("Fetching notes with embeddings...")
+  const notes = await prisma.note.findMany({
+    where: {
+      embedding: { not: null }
+    },
+    select: {
+      id: true,
+      embedding: true
+    }
+  })
+
+  console.log(`Found ${notes.length} notes with an embedding.`)
+  
+  if (notes.length === 0) {
+    console.log("Nothing to migrate.")
+    return
+  }
+
+  let count = 0
+  for (const note of notes) {
+    if (!note.embedding) continue
+
+    await prisma.noteEmbedding.upsert({
+      where: { noteId: note.id },
+      create: {
+        noteId: note.id,
+        embedding: note.embedding
+      },
+      update: {
+        embedding: note.embedding
+      }
+    })
+    count++
+    if (count % 10 === 0) {
+      console.log(`Migrated ${count}/${notes.length}...`)
+    }
+  }
+
+  console.log(`✅ Successfully migrated ${count} note embeddings to the NoteEmbedding table.`)
+}
+
+main()
+  .catch((e) => {
+    console.error("Migration failed:", e)
+    process.exit(1)
+  })
+  .finally(async () => {
+    await prisma.$disconnect()
+  })