feat(runtime): add bounded foreground ad hoc child route

apps/desktop/e2e/settings.spec.ts

@@ -180,6 +180,28 @@ test('wide settings gutters scroll the whole main pane', async ({ window: page }
   await expect(content).toBeVisible();
 });
 
+test('temporary subagent policy can be enabled and persisted', async ({ window: page }) => {
+  await ensureSidebarExpanded(page);
+  await page.getByRole('button', { name: '设置', exact: true }).click();
+  await page.getByRole('button', { name: '子 Agent', exact: true }).click();
+
+  const main = page.getByRole('main', { name: '设置内容' });
+  await expect(main.getByRole('heading', { name: '临时子 Agent' })).toBeVisible();
+  const enabled = main.getByRole('switch', { name: '允许临时子 Agent' });
+  await enabled.click();
+  await main.getByRole('button', { name: '保存临时策略' }).click();
+
+  await expect
+    .poll(async () => (await page.evaluate(() => window.maka.settings.get())).subagents.adHoc)
+    .toMatchObject({
+      enabled: true,
+      maxProfile: 'local_read',
+      connectionSlug: 'e2e',
+      model: 'claude-sonnet-4-5-20250929',
+    });
+  await expect(enabled).toBeChecked();
+});
+
 test('appearance choice content stays vertically centered in stretched grid rows', async ({ window: page }) => {
   await page.evaluate(async () => {
     await window.maka.settings.update({ personalization: { uiLocale: 'en' } });

apps/desktop/src/main/__tests__/runtime-host-settings-ipc-main.test.ts

@@ -135,12 +135,17 @@ function createModuleFixture(options: {
     async updateRuntimePolicy(
       createMutation: (value: RuntimePolicy) => {
         kind: string;
-        value: RuntimePolicy["networkProxy"];
+        value: unknown;
       },
     ) {
       const mutation = createMutation(policy);
       if (mutation.kind === "set_network_proxy") {
-        policy = { ...policy, networkProxy: mutation.value };
+        policy = { ...policy, networkProxy: mutation.value as RuntimePolicy["networkProxy"] };
+      } else if (mutation.kind === "set_subagents") {
+        policy = {
+          ...policy,
+          subagents: mutation.value as RuntimePolicy["subagents"],
+        };
       }
       policyRevision += 1;
       return { revision: policyRevision, policy };
@@ -265,6 +270,22 @@ test("runtime settings project credential status without a password value", asyn
   assert.equal("password" in settings.network.proxy, false);
 });
 
+test("subagent preset updates preserve the existing ad-hoc policy", async () => {
+  const fixture = createModuleFixture();
+  const current = fixture.policy();
+  const adHoc = {
+    enabled: true,
+    maxProfile: "local_read" as const,
+    connectionSlug: "worker-provider",
+    model: "gpt-5-mini",
+  };
+  // Seed the host policy through the same mutation seam used by the module.
+  await fixture.module.update({ subagents: { presets: [], adHoc } });
+  await fixture.module.update({ subagents: { presets: [] } });
+  assert.deepEqual(fixture.policy().subagents, { presets: [], adHoc });
+  assert.notDeepEqual(fixture.policy(), current);
+});
+
 test("spread-back derived and legacy password fields never enter Runtime policy", async () => {
   const fixture = createModuleFixture({ configured: true });
 

apps/desktop/src/main/runtime-host-settings-ipc-main.ts

@@ -405,9 +405,12 @@ async function applyHostPatchWithoutLane(
     }
   }
   if (patch.subagents) {
-    await client.updateRuntimePolicy(() => ({
+    await client.updateRuntimePolicy((policy) => ({
       kind: "set_subagents",
-      value: patch.subagents!,
+      value: {
+        ...policy.subagents,
+        ...patch.subagents,
+      },
     }));
   }
   return skippedCredentials;

apps/desktop/src/renderer/locales/settings-subagents-copy.ts

@@ -29,6 +29,21 @@ type ProfileCopy = {
 };
 
 export type SubagentSettingsCopy = {
+  adHoc: {
+    title: string;
+    description: string;
+    enabled: string;
+    enabledDescription: string;
+    profile: string;
+    profileDescription: string;
+    connection: string;
+    model: string;
+    thinking: string;
+    noConnection: string;
+    noModel: string;
+    save: string;
+    saveFailed: string;
+  };
   section: {
     title: string;
     count(total: number): string;
@@ -101,6 +116,21 @@ export type SubagentSettingsCopy = {
 
 const SETTINGS_SUBAGENTS_COPY_BY_LOCALE = {
   zh: {
+    adHoc: {
+      title: '临时子 Agent',
+      description: '明确启用后，主 Agent 才能创建一次性的任务角色。这里固定它可用的最高能力、连接和模型。',
+      enabled: '允许临时子 Agent',
+      enabledDescription: '关闭后，临时角色不会出现在 agent_list 中，也无法通过 agent_spawn 创建。',
+      profile: '最高能力 Profile',
+      profileDescription: '临时角色只能使用不高于此 Profile 的固定能力边界。',
+      connection: '模型连接',
+      model: '模型',
+      thinking: '思考级别',
+      noConnection: '请先在“模型”页启用一个模型连接。',
+      noModel: '所选连接没有已启用的模型。',
+      save: '保存临时策略',
+      saveFailed: '保存临时子 Agent 策略失败',
+    },
     section: {
       title: '已批准的子 Agent',
       count: (total) => `共 ${total} 个配置`,
@@ -183,6 +213,21 @@ const SETTINGS_SUBAGENTS_COPY_BY_LOCALE = {
     },
   },
   en: {
+    adHoc: {
+      title: 'Temporary subagent',
+      description: 'When explicitly enabled, the main agent may create one-off task roles. These settings fix their maximum capability, connection, and model.',
+      enabled: 'Allow temporary subagents',
+      enabledDescription: 'When off, the route is omitted from agent_list and agent_spawn cannot create it.',
+      profile: 'Maximum capability profile',
+      profileDescription: 'Temporary roles cannot exceed this fixed capability boundary.',
+      connection: 'Model connection',
+      model: 'Model',
+      thinking: 'Thinking level',
+      noConnection: 'Enable a model connection on the Models page first.',
+      noModel: 'The selected connection has no enabled models.',
+      save: 'Save temporary policy',
+      saveFailed: 'Failed to save temporary subagent policy',
+    },
     section: {
       title: 'Approved subagents',
       count: (total) => `${total} presets`,