fix: database connection problem debug

postgre_mcp_server.py

@@ -42,6 +42,9 @@ async def db_lifespan(server: FastMCP) -> AsyncIterator[DbContext]:
     load_dotenv()
     dsn = os.getenv("DB_URL")
     schema = os.getenv("DB_SCHEMA")
+    
+    print("DEBUG: DB_URL =", os.getenv("DB_URL"))
+
     pool = await asyncpg.create_pool(
         dsn,
         min_size=1,