feat: add configurable Antigravity user agent version

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,