fix: missing pgvector in CLI

Fixes https://github.com/langchain-ai/langgraph/issues/3164

libs/cli/langgraph_cli/docker.py

@@ -170,13 +170,14 @@ def compose_as_dict(
     # Add Postgres service before langgraph-api if it is needed
     if include_db:
         services["langgraph-postgres"] = {
-            "image": "postgres:16",
+            "image": "pgvector/pgvector:pg16",
             "ports": ['"5433:5432"'],
             "environment": {
                 "POSTGRES_DB": "postgres",
                 "POSTGRES_USER": "postgres",
                 "POSTGRES_PASSWORD": "postgres",
             },
+            "command": ["postgres", "-c", "shared_preload_libraries=vector"],
             "volumes": ["langgraph-data:/var/lib/postgresql/data"],
             "healthcheck": {
                 "test": "pg_isready -U postgres",

libs/cli/tests/unit_tests/test_docker.py

@@ -115,13 +115,17 @@ services:
             timeout: 1s
             retries: 5
     langgraph-postgres:
-        image: postgres:16
+        image: pgvector/pgvector:pg16
         ports:
             - "5433:5432"
         environment:
             POSTGRES_DB: postgres
             POSTGRES_USER: postgres
             POSTGRES_PASSWORD: postgres
+        command:
+            - postgres
+            - -c
+            - shared_preload_libraries=vector
         volumes:
             - langgraph-data:/var/lib/postgresql/data
         healthcheck: