fix: load .env file via python-dotenv for local development

src/tryton_mcp/config.py

@@ -1,10 +1,15 @@
 import os
 from contextlib import asynccontextmanager
 from dataclasses import dataclass, field
+from pathlib import Path
 from typing import Optional
 
+from dotenv import load_dotenv
 from sabatron_tryton_rpc_client.client import Client
 
+project_root = Path(__file__).parent.parent.parent
+load_dotenv(project_root / ".env")
+
 
 @dataclass
 class TrytonSettings: