refactor(i18n): remove unnecessary translation for brand names

- Use hardcoded "Claude", "Codex", "Gemini" instead of i18n keys
- Brand names should not be translated across different locales
- Simplifies code by removing useTranslation hook from AppSwitcher
- Reduces maintenance overhead in translation files

src/components/mcp/McpFormModal.tsx

@@ -111,8 +111,7 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
 
   // 判断是否使用 TOML 格式
   const useToml = appId === "codex";
-  const syncTargetLabel =
-    appId === "claude" ? t("apps.codex") : t("apps.claude");
+  const syncTargetLabel = appId === "claude" ? "Codex" : "Claude";
   const otherAppType: AppId = appId === "claude" ? "codex" : "claude";
   const syncCheckboxId = useMemo(() => `sync-other-side-${appId}`, [appId]);