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.

src/i18n/messages.ts

@@ -433,6 +433,8 @@ export const messages: I18nMessages = {
         description: 'Customize the look and feel of the application.',
         themeSection: 'Theme Settings',
         languageSection: 'Language',
+        launchAtStartupTitle: 'Launch at startup',
+        launchAtStartupDescription: 'Start the app automatically after you sign in',
         gatewayTitle: 'Gateway',
         gatewayDescription: 'View the current Gateway state and basic runtime controls.',
         gatewayStatusLabel: 'Status',
@@ -911,6 +913,8 @@ export const messages: I18nMessages = {
         description: '自定义应用的外观与使用体验。',
         themeSection: '主题设置',
         languageSection: '语言',
+        launchAtStartupTitle: '开机自动启动',
+        launchAtStartupDescription: '登录系统后自动启动应用',
         gatewayTitle: '网关',
         gatewayDescription: '查看当前网关状态与基础运行控制。',
         gatewayStatusLabel: '状态',
@@ -1389,6 +1393,8 @@ export const messages: I18nMessages = {
         description: 'アプリの見た目と操作感をカスタマイズします。',
         themeSection: 'テーマ設定',
         languageSection: '言語',
+        launchAtStartupTitle: 'システム起動時に自動起動',
+        launchAtStartupDescription: 'システムにログインした後、アプリを自動的に起動します',
         gatewayTitle: 'ゲートウェイ',
         gatewayDescription: '現在のゲートウェイ状態と基本的なランタイム操作を確認します。',
         gatewayStatusLabel: '状態',