feat: add slides generation tool with multiple slide types

- Add slides.tool.ts with support for title, bullets, chart, stats, table, cards, timeline, quote, comparison, equation, image, summary slide types
- Chart types: bar, horizontal-bar, line, donut, radar
- Integrate with agent executor and canvas system
- Add multilingual support (en/fr)
- Various UI improvements and bug fixes

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

memento-note/lib/embeddings.ts

@@ -0,0 +1,18 @@
+import prisma from '@/lib/prisma'
+
+/**
+ * Upsert a note embedding into the NoteEmbedding table.
+ * Uses a single SQL UPSERT to avoid race conditions.
+ * The SQL template is fully static — no user data is interpolated into the query string.
+ */
+export async function upsertNoteEmbedding(noteId: string, embedding: number[]): Promise<void> {
+  const vecStr = `[${embedding.join(',')}]`
+  await prisma.$executeRawUnsafe(
+    `INSERT INTO "NoteEmbedding" ("id", "noteId", "embedding", "createdAt", "updatedAt")
+     VALUES (gen_random_uuid(), $1, $2::vector, now(), now())
+     ON CONFLICT ("noteId")
+     DO UPDATE SET "embedding" = EXCLUDED."embedding", "updatedAt" = now()`,
+    noteId,
+    vecStr
+  )
+}