fix: L2-normalize local embedding vectors to fix semantic search (#5332)

* fix: L2-normalize local embedding vectors to fix semantic search

* fix: handle non‑finite magnitude in L2 normalization and remove stale test reset

* refactor: add braces to l2Normalize guard clause in embeddings

* fix: sanitize local embeddings (#5332) (thanks @akramcodez)

---------

Co-authored-by: Gustavo Madeira Santana <gumadeiras@gmail.com>

src/memory/embeddings.ts

@@ -6,6 +6,15 @@ import { createGeminiEmbeddingProvider, type GeminiEmbeddingClient } from "./emb
 import { createOpenAiEmbeddingProvider, type OpenAiEmbeddingClient } from "./embeddings-openai.js";
 import { importNodeLlamaCpp } from "./node-llama.js";
 
+function sanitizeAndNormalizeEmbedding(vec: number[]): number[] {
+  const sanitized = vec.map((value) => (Number.isFinite(value) ? value : 0));
+  const magnitude = Math.sqrt(sanitized.reduce((sum, value) => sum + value * value, 0));
+  if (magnitude < 1e-10) {
+    return sanitized;
+  }
+  return sanitized.map((value) => value / magnitude);
+}
+
 export type { GeminiEmbeddingClient } from "./embeddings-gemini.js";
 export type { OpenAiEmbeddingClient } from "./embeddings-openai.js";
 
@@ -98,14 +107,14 @@ async function createLocalEmbeddingProvider(
     embedQuery: async (text) => {
       const ctx = await ensureContext();
       const embedding = await ctx.getEmbeddingFor(text);
-      return Array.from(embedding.vector);
+      return sanitizeAndNormalizeEmbedding(Array.from(embedding.vector));
     },
     embedBatch: async (texts) => {
       const ctx = await ensureContext();
       const embeddings = await Promise.all(
         texts.map(async (text) => {
           const embedding = await ctx.getEmbeddingFor(text);
-          return Array.from(embedding.vector);
+          return sanitizeAndNormalizeEmbedding(Array.from(embedding.vector));
         }),
       );
       return embeddings;