fix: resolve NameError for Config in wallet_daemon_client.py

Config was used as a type annotation in WalletDaemonClient.__init__ but
never imported, causing NameError at class definition time. Fixed by
importing Config under TYPE_CHECKING guard and using string annotation
'Config' to defer resolution to type-checkers only.

cli/utils/wallet_daemon_client.py

@@ -6,7 +6,7 @@ This module provides a client for interacting with the AITBC wallet daemon.
 import sys
 import json
 import base64
-from typing import Dict, Any, Optional, List
+from typing import TYPE_CHECKING, Dict, Any, Optional, List
 from pathlib import Path
 from dataclasses import dataclass
 
@@ -15,6 +15,9 @@ from aitbc import AITBCHTTPClient, NetworkError
 sys.path.insert(0, "/opt/aitbc/cli")
 from utils import error, success
 
+if TYPE_CHECKING:
+    from core.config import Config
+
 
 @dataclass
 class ChainInfo:
@@ -62,7 +65,7 @@ class WalletMigrationResult:
 class WalletDaemonClient:
     """Client for interacting with AITBC wallet daemon"""
     
-    def __init__(self, config: Config):
+    def __init__(self, config: "Config"):
         self.config = config
         self.base_url = config.wallet_url.rstrip('/')
         self.timeout = getattr(config, 'timeout', 30)