fix: organize-notebook orphelin (sed console.log) + migration DB indexes

- organize-notebook.ts: lignes orphelines supprimées (console.log multi-ligne cassé par sed)
- Migration 20260629000000: CREATE INDEX contentUpdatedAt DESC + isPublic sur Note
- schema.prisma: commentaire SQL brut retiré (invalidait prisma)

memento-note/prisma/migrations/20260629000000_add_note_indexes/migration.sql

@@ -0,0 +1,3 @@
+-- Add indexes for performance
+CREATE INDEX IF NOT EXISTS "Note_contentUpdatedAt_idx" ON "Note" ("contentUpdatedAt" DESC);
+CREATE INDEX IF NOT EXISTS "Note_isPublic_idx" ON "Note" ("isPublic");

memento-note/prisma/schema.prisma

@@ -749,10 +749,6 @@ model DocumentChunk {
   @@index([attachmentId, chunkIndex])
 }
 
--- Index vectoriel pour recherche sémantique sur DocumentChunk (HNSW)
--- CREATE INDEX IF NOT EXISTS document_chunk_embedding_hnsw_idx
--- ON "DocumentChunk" USING hnsw ("embedding" vector_cosine_ops);
-
 // ===== BYOK (Story 3.5) =====
 
 model UserAPIKey {