feat(cli): add direct argument support for /approval-mode command

Allow users to set approval mode directly via argument instead of
opening the dialog. For example:
- /approval-mode plan
- /approval-mode yolo
- /approval-mode auto-edit
- /approval-mode default

If no argument is provided, the dialog opens as before.
If an invalid argument is provided, an error message shows valid options.

Also adds tab completion for mode arguments.

Fixes #1353

packages/cli/src/i18n/locales/zh.js

@@ -88,6 +88,9 @@ export default {
   'No tools available': '没有可用工具',
   'View or change the approval mode for tool usage':
     '查看或更改工具使用的审批模式',
+  'Invalid approval mode "{{arg}}". Valid modes: {{modes}}':
+    '无效的审批模式 "{{arg}}"。有效模式：{{modes}}',
+  'Approval mode set to "{{mode}}"': '审批模式已设置为 "{{mode}}"',
   'View or change the language setting': '查看或更改语言设置',
   'change the theme': '更改主题',
   'Select Theme': '选择主题',