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/AppSwitcher.tsx

@@ -1,6 +1,5 @@
 import type { AppId } from "@/lib/api";
 import { ClaudeIcon, CodexIcon, GeminiIcon } from "./BrandIcons";
-import { useTranslation } from "react-i18next";
 
 interface AppSwitcherProps {
   activeApp: AppId;
@@ -8,7 +7,6 @@ interface AppSwitcherProps {
 }
 
 export function AppSwitcher({ activeApp, onSwitch }: AppSwitcherProps) {
-  const { t } = useTranslation();
   const handleSwitch = (app: AppId) => {
     if (app === activeApp) return;
     onSwitch(app);
@@ -33,7 +31,7 @@ export function AppSwitcher({ activeApp, onSwitch }: AppSwitcherProps) {
               : "text-gray-500 dark:text-gray-400 group-hover:text-[#D97757] dark:group-hover:text-[#D97757] transition-colors duration-200"
           }
         />
-        <span>{t("apps.claude")}</span>
+        <span>Claude</span>
       </button>
 
       <button
@@ -46,7 +44,7 @@ export function AppSwitcher({ activeApp, onSwitch }: AppSwitcherProps) {
         }`}
       >
         <CodexIcon size={16} />
-        <span>{t("apps.codex")}</span>
+        <span>Codex</span>
       </button>
 
       <button
@@ -66,7 +64,7 @@ export function AppSwitcher({ activeApp, onSwitch }: AppSwitcherProps) {
               : "text-gray-500 dark:text-gray-400 group-hover:text-[#4285F4] dark:group-hover:text-[#4285F4] transition-colors duration-200"
           }
         />
-        <span>{t("apps.gemini")}</span>
+        <span>Gemini</span>
       </button>
     </div>
   );

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]);