i18n: complete internationalization for settings panel

- Add missing translation keys for all hint texts and descriptions
- Remove all hardcoded defaultValue parameters from components
- Add translations for window behavior, directory settings, and theme settings
- Add translations for provider-related UI elements
- Improve consistency across Chinese and English translations

Translation additions:
- common.toggleTheme
- settings.windowBehaviorHint, claudeConfigDirDescription, codexConfigDirDescription
- provider.* (12 new keys)
- providerForm.* (15 new keys)
- providerPreset.* (4 new keys)

Modified files: 10
Lines changed: +132 -74

src/components/mode-toggle.tsx

@@ -22,7 +22,7 @@ export function ModeToggle() {
       <Sun className="h-4 w-4 rotate-0 scale-100 transition-all dark:-rotate-90 dark:scale-0" />
       <Moon className="absolute h-4 w-4 rotate-90 scale-0 transition-all dark:rotate-0 dark:scale-100" />
       <span className="sr-only">
-        {t("common.toggleTheme", { defaultValue: "切换主题" })}
+        {t("common.toggleTheme")}
       </span>
     </Button>
   );