add second layer of result validation

backend/services/embedding.service.js

@@ -0,0 +1,25 @@
+import { VoyageAIClient } from "voyageai";
+
+const client = new VoyageAIClient({
+  apiKey: process.env.VOYAGEAI_API_KEY,
+});
+
+/**
+ * @param {Array<{id: string, text: string}>} notes
+ * @returns {Promise<Map<string, number[]>>} noteId → embedding vector
+ */
+export const embedNotes = async (notes) => {
+  const texts = notes.map((n) => n.text);
+
+  const response = await client.embed({
+    input: texts,
+    model: "voyage-3-lite",
+  });
+
+  const embeddingMap = new Map();
+  response.data.forEach((item, i) => {
+    embeddingMap.set(notes[i].id, item.embedding);
+  });
+
+  return embeddingMap;
+};