Fix help text for `--disable-echo-cancellation` to clarify the default behavior is not disabled

src/voice_dialogue/cli/args.py

@@ -72,7 +72,7 @@ def create_argument_parser():
         '--disable-echo-cancellation',
         action='store_true',
         default=False,
-        help='禁用回声消除功能 (默认: 启用)'
+        help='禁用回声消除功能 (默认: 不禁用)'
     )
 
     # API服务器模式参数