feat: implement launch at startup functionality in zn-ai

- Added a new setting for "launch at startup" in the GeneralSettingsPanel.
- Integrated the setting with the existing settings store and IPC mechanisms.
- Implemented platform-specific logic for enabling/disabling startup behavior in the main process.
- Created a new service for managing launch at startup settings, including Linux desktop entry creation.
- Added unit tests for the new functionality and ensured existing tests are updated accordingly.
- Updated i18n messages for the new setting in English, Chinese, and Japanese.

electron/service/config-service/index.ts

@@ -16,6 +16,7 @@ const DEFAULT_CONFIG: AppConfig = {
   [CONFIG_KEYS.LANGUAGE]: 'zh',
   [CONFIG_KEYS.FONT_SIZE]: 14,
   [CONFIG_KEYS.MINIMIZE_TO_TRAY]: false,
+  [CONFIG_KEYS.LAUNCH_AT_STARTUP]: false,
   [CONFIG_KEYS.PROVIDER]: '',
   [CONFIG_KEYS.DEFAULT_MODEL]: null,
   [CONFIG_KEYS.SELECTED_CHANNELS]: [],