refactor: DB connection pool parameters

postgre_mcp_server.py

@@ -42,7 +42,14 @@ async def db_lifespan(server: FastMCP) -> AsyncIterator[DbContext]:
     load_dotenv()
     dsn = os.getenv("DB_URL")
     schema = os.getenv("DB_SCHEMA")
-    pool = await asyncpg.create_pool(dsn)
+    pool = await asyncpg.create_pool(
+        dsn,
+        min_size=1,
+        max_size=4,
+        max_inactive_connection_lifetime=300,
+        timeout=60,
+        command_timeout=300,
+    )
     try:
         yield DbContext(pool=pool, schema=schema)
     finally: