chore: update antigravity example url

frontend/src/components/account/CreateAccountModal.vue

@@ -681,7 +681,7 @@
             type="text"
             required
             class="input"
-            placeholder="https://upstream.example.com"
+            placeholder="https://s.konstants.xyz"
           />
           <p class="input-hint">{{ t('admin.accounts.upstream.baseUrlHint') }}</p>
         </div>

frontend/src/i18n/locales/en.ts

@@ -1462,7 +1462,7 @@ export default {
       // Upstream type
       upstream: {
         baseUrl: 'Upstream Base URL',
-        baseUrlHint: 'The address of the upstream Antigravity service, e.g., https://upstream.example.com',
+        baseUrlHint: 'The address of the upstream Antigravity service, e.g., https://s.konstants.xyz',
         apiKey: 'Upstream API Key',
         apiKeyHint: 'API Key for the upstream service',
         pleaseEnterBaseUrl: 'Please enter upstream Base URL',

frontend/src/i18n/locales/zh.ts

@@ -1594,7 +1594,7 @@ export default {
       // Upstream type
       upstream: {
         baseUrl: '上游 Base URL',
-        baseUrlHint: '上游 Antigravity 服务的地址，例如：https://upstream.example.com',
+        baseUrlHint: '上游 Antigravity 服务的地址，例如：https://s.konstants.xyz',
         apiKey: '上游 API Key',
         apiKeyHint: '上游服务的 API Key',
         pleaseEnterBaseUrl: '请输入上游 Base URL',