feat: add configurable Antigravity user agent version

frontend/src/api/admin/settings.ts

@@ -478,6 +478,7 @@ export interface SystemSettings {
   enable_cch_signing: boolean;
   enable_anthropic_cache_ttl_1h_injection: boolean;
   rewrite_message_cache_control: boolean;
+  antigravity_user_agent_version: string;
   web_search_emulation_enabled?: boolean;
 
   // Payment configuration
@@ -675,6 +676,7 @@ export interface UpdateSettingsRequest {
   enable_cch_signing?: boolean;
   enable_anthropic_cache_ttl_1h_injection?: boolean;
   rewrite_message_cache_control?: boolean;
+  antigravity_user_agent_version?: string;
   // Payment configuration
   payment_enabled?: boolean;
   risk_control_enabled?: boolean;

frontend/src/i18n/locales/en.ts

@@ -5337,6 +5337,9 @@ export default {
         anthropicCacheTTL1hInjectionHint: 'When enabled, existing ephemeral cache_control blocks in Anthropic OAuth/Setup Token request bodies are forced to 1h; response usage is billed back as 5m by default, with account-level TTL billing override taking priority.',
         rewriteMessageCacheControl: 'Rewrite Message Cache Breakpoints',
         rewriteMessageCacheControlHint: 'Default off: preserve client cache_control on message content blocks. When enabled, client breakpoints are stripped and proxy breakpoints are injected for clients that do not manage caching themselves.',
+        antigravityUserAgentVersion: 'Antigravity UA Version',
+        antigravityUserAgentVersionPlaceholder: '1.23.2',
+        antigravityUserAgentVersionHint: 'Leave empty to use ANTIGRAVITY_USER_AGENT_VERSION or the built-in default 1.23.2; when set, the admin setting takes precedence.',
       },
       webSearchEmulation: {
         title: 'Web Search Emulation',

frontend/src/i18n/locales/zh.ts

@@ -5496,6 +5496,9 @@ export default {
         anthropicCacheTTL1hInjectionHint: '开启后，对 Anthropic OAuth/Setup Token 请求体中已有的 ephemeral 缓存块强制写入 1h；响应 usage 默认按 5m 回写计费，账号级 TTL 计费设置优先。',
         rewriteMessageCacheControl: '改写消息缓存断点',
         rewriteMessageCacheControlHint: '默认关闭，保留客户端在 messages 内容块中的 cache_control。开启后会清除客户端断点并注入代理断点，适合不自行管理缓存策略的客户端。',
+        antigravityUserAgentVersion: 'Antigravity UA 版本',
+        antigravityUserAgentVersionPlaceholder: '1.23.2',
+        antigravityUserAgentVersionHint: '留空时使用 ANTIGRAVITY_USER_AGENT_VERSION 或内置默认值 1.23.2；填写后后台设置优先。',
       },
       webSearchEmulation: {
         title: 'Web Search 模拟',

frontend/src/views/admin/SettingsView.vue

@@ -3451,6 +3451,36 @@
                 </div>
                 <Toggle v-model="form.rewrite_message_cache_control" />
               </div>
+
+              <!-- Antigravity UA 版本 -->
+              <div>
+                <label
+                  class="mb-2 block text-sm font-medium text-gray-700 dark:text-gray-300"
+                >
+                  {{
+                    t(
+                      "admin.settings.gatewayForwarding.antigravityUserAgentVersion",
+                    )
+                  }}
+                </label>
+                <input
+                  v-model="form.antigravity_user_agent_version"
+                  type="text"
+                  class="input max-w-xs font-mono text-sm"
+                  :placeholder="
+                    t(
+                      'admin.settings.gatewayForwarding.antigravityUserAgentVersionPlaceholder',
+                    )
+                  "
+                />
+                <p class="mt-1.5 text-xs text-gray-500 dark:text-gray-400">
+                  {{
+                    t(
+                      "admin.settings.gatewayForwarding.antigravityUserAgentVersionHint",
+                    )
+                  }}
+                </p>
+              </div>
             </div>
           </div>
           <!-- Web Search Emulation -->
@@ -6571,6 +6601,7 @@ const form = reactive<SettingsForm>({
   enable_cch_signing: false,
   enable_anthropic_cache_ttl_1h_injection: false,
   rewrite_message_cache_control: false,
+  antigravity_user_agent_version: "",
   // Balance & quota notification
   balance_low_notify_enabled: false,
   balance_low_notify_threshold: 0,
@@ -7642,6 +7673,8 @@ async function saveSettings() {
       enable_anthropic_cache_ttl_1h_injection:
         form.enable_anthropic_cache_ttl_1h_injection,
       rewrite_message_cache_control: form.rewrite_message_cache_control,
+      antigravity_user_agent_version:
+        form.antigravity_user_agent_version?.trim() || "",
       // Payment configuration
       payment_enabled: form.payment_enabled,
       risk_control_enabled: form.risk_control_enabled,

frontend/src/views/admin/__tests__/SettingsView.spec.ts

@@ -370,6 +370,7 @@ const baseSettingsResponse = {
   enable_cch_signing: false,
   enable_anthropic_cache_ttl_1h_injection: false,
   rewrite_message_cache_control: false,
+  antigravity_user_agent_version: "",
   payment_enabled: true,
   payment_min_amount: 1,
   payment_max_amount: 10000,
@@ -622,6 +623,26 @@ describe("admin SettingsView payment visible method controls", () => {
     );
   });
 
+  it("submits Antigravity user agent version gateway setting", async () => {
+    getSettings.mockResolvedValueOnce({
+      ...baseSettingsResponse,
+      antigravity_user_agent_version: "1.23.2",
+    });
+
+    const wrapper = mountView();
+
+    await flushPromises();
+    await wrapper.find("form").trigger("submit.prevent");
+    await flushPromises();
+
+    expect(updateSettings).toHaveBeenCalledTimes(1);
+    expect(updateSettings).toHaveBeenCalledWith(
+      expect.objectContaining({
+        antigravity_user_agent_version: "1.23.2",
+      }),
+    );
+  });
+
   it("updates provider enablement immediately and reloads providers", async () => {
     const provider = {
       id: 7,