feat(settings): add option to skip Claude Code first-run confirmation

Add a new setting to automatically skip Claude Code's onboarding screen
by writing hasCompletedOnboarding=true to ~/.claude.json. The setting
defaults to enabled for better user experience.

- Add set/clear_has_completed_onboarding functions in claude_mcp.rs
- Add Tauri commands and frontend API integration
- Add toggle in WindowSettings with i18n support (en/zh/ja)
- Fix hardcoded Chinese text in tests to use i18n keys

src/hooks/useSettingsForm.ts

@@ -83,6 +83,7 @@ export function useSettingsForm(): UseSettingsFormResult {
       minimizeToTrayOnClose: data.minimizeToTrayOnClose ?? true,
       enableClaudePluginIntegration:
         data.enableClaudePluginIntegration ?? false,
+      skipClaudeOnboarding: data.skipClaudeOnboarding ?? true,
       claudeConfigDir: sanitizeDir(data.claudeConfigDir),
       codexConfigDir: sanitizeDir(data.codexConfigDir),
       language: normalizedLanguage,
@@ -102,6 +103,7 @@ export function useSettingsForm(): UseSettingsFormResult {
             showInTray: true,
             minimizeToTrayOnClose: true,
             enableClaudePluginIntegration: false,
+            skipClaudeOnboarding: true,
             language: readPersistedLanguage(),
           } as SettingsFormState);
 
@@ -136,6 +138,7 @@ export function useSettingsForm(): UseSettingsFormResult {
         minimizeToTrayOnClose: serverData.minimizeToTrayOnClose ?? true,
         enableClaudePluginIntegration:
           serverData.enableClaudePluginIntegration ?? false,
+        skipClaudeOnboarding: serverData.skipClaudeOnboarding ?? true,
         claudeConfigDir: sanitizeDir(serverData.claudeConfigDir),
         codexConfigDir: sanitizeDir(serverData.codexConfigDir),
         language: normalizedLanguage,