fix(postgres): Handle vector extension creation properly (#1561)

- Add proper checks for vector extension existence

- Create extensions schema if not exists

- Add extensions schema to search path

- Ensure idempotent schema creation

Author: AIFlowML

packages/adapter-postgres/schema.sql

@@ -10,10 +10,26 @@
 -- DROP TABLE IF EXISTS rooms CASCADE;
 -- DROP TABLE IF EXISTS accounts CASCADE;
 
+-- Create extensions schema first
+CREATE SCHEMA IF NOT EXISTS extensions;
+
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1
+        FROM pg_extension
+        WHERE extname = 'vector'
+    ) THEN
+        CREATE EXTENSION vector
+        SCHEMA extensions;
+    END IF;
+END $$;
 
-CREATE EXTENSION IF NOT EXISTS vector;
 CREATE EXTENSION IF NOT EXISTS fuzzystrmatch;
 
+-- Add extensions schema to search path
+SET search_path TO public, extensions;
+
 -- Create a function to determine vector dimension
 CREATE OR REPLACE FUNCTION get_embedding_dimension()
 RETURNS INTEGER AS $$