chore: snapshot before performance optimization

keep-notes/lib/ai/services/embedding.service.ts

@@ -175,26 +175,17 @@ export class EmbeddingService {
   }
 
   /**
-   * Serialize embedding to JSON-safe format (for storage)
+   * Pass-through — embeddings are stored as native JSONB in PostgreSQL
    */
-  serialize(embedding: number[]): string {
-    return JSON.stringify(embedding)
+  serialize(embedding: number[]): number[] {
+    return embedding
   }
 
   /**
-   * Deserialize embedding from JSON string
+   * Pass-through — embeddings come back already parsed from PostgreSQL
    */
-  deserialize(jsonString: string): number[] {
-    try {
-      const parsed = JSON.parse(jsonString)
-      if (!Array.isArray(parsed)) {
-        throw new Error('Invalid embedding format')
-      }
-      return parsed
-    } catch (error) {
-      console.error('Error deserializing embedding:', error)
-      throw new Error('Failed to deserialize embedding')
-    }
+  deserialize(embedding: number[]): number[] {
+    return embedding
   }
 
   /**