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/components/settings/WindowSettings.tsx

@@ -46,6 +46,14 @@ export function WindowSettings({ settings, onChange }: WindowSettingsProps) {
             onChange({ enableClaudePluginIntegration: value })
           }
         />
+
+        <ToggleRow
+          icon={<MonitorUp className="h-4 w-4 text-cyan-500" />}
+          title={t("settings.skipClaudeOnboarding")}
+          description={t("settings.skipClaudeOnboardingDescription")}
+          checked={!!settings.skipClaudeOnboarding}
+          onCheckedChange={(value) => onChange({ skipClaudeOnboarding: value })}
+        />
       </div>
     </section>
   );