feat(ui): surface @mux tool optimization + approval opt-out link

Two small discoverability nudges around tool optimization:

- FeatureSets tab: add a branded "Let your AI build these for you"
  hint showing the `@mux optimize` chat affordance — the assistant can
  discover tools, compose a FeatureSet, and pin it to the current
  folder, each gated behind a one-click approval.

- Meta-tool approval dialog: add a "Prefer not to be asked? Manage
  approval prompts" link that denies the current request (fail-closed,
  so the client is not left hanging for the 60s broker timeout) and
  routes to the Built-in tab, where the "Require approval for tool
  changes" switch can turn these prompts off.

Covered by a new MetaToolApprovalDialog test asserting the link denies
and navigates to builtin-servers.

Signed-off-by: Mohammod Al Amin Ashik <maa.ashik00@gmail.com>

Author: its-mash

apps/desktop/src/features/featuresets/FeatureSetsPage.tsx

@@ -12,6 +12,7 @@ import {
   AlertCircle,
   CheckCircle2,
   Zap,
+  Sparkles,
 } from 'lucide-react';
 import {
   Card,
@@ -268,6 +269,32 @@ export function FeatureSetsPage() {
           </div>
         </div>
 
+        {/* @mux self-optimization hint — let the assistant curate the toolset from chat */}
+        <div className="flex-shrink-0 px-8 pt-6">
+          <div
+            className="mx-auto flex max-w-[2000px] items-start gap-3 rounded-xl border border-violet-200/70 bg-gradient-to-r from-violet-50/60 to-transparent p-4 dark:border-violet-800/40 dark:from-violet-900/15"
+            data-testid="featuresets-mux-hint"
+          >
+            <div className="mt-0.5 flex h-8 w-8 items-center justify-center rounded-lg bg-gradient-to-br from-violet-500 to-fuchsia-500 text-white shadow-[0_4px_10px_-2px_rgb(139_92_246/0.45)]">
+              <Sparkles className="h-4 w-4 fill-current" />
+            </div>
+            <div className="min-w-0 flex-1">
+              <p className="text-sm font-semibold text-[rgb(var(--foreground))]">
+                Let your AI build these for you
+              </p>
+              <p className="mt-0.5 text-xs leading-relaxed text-[rgb(var(--muted))]">
+                In any connected client, just say{' '}
+                <code className="rounded bg-[rgb(var(--surface))] px-1.5 py-0.5 font-mono text-[11px] text-violet-600 dark:text-violet-300">
+                  @mux optimize
+                </code>{' '}
+                — your assistant can discover the available tools, compose a FeatureSet, and pin it
+                to the current folder. Every change is gated behind a one-click approval, so you
+                stay in control.
+              </p>
+            </div>
+          </div>
+        </div>
+
         {/* Feature-set model explainer */}
         <div className="flex-shrink-0 px-8 pt-6">
           <div className="mx-auto flex max-w-[2000px] items-start gap-3 rounded-xl border border-emerald-200/70 bg-gradient-to-r from-emerald-50/60 to-transparent p-4 dark:border-emerald-800/40 dark:from-emerald-900/15">

apps/desktop/src/features/metaTools/MetaToolApprovalDialog.tsx

@@ -3,6 +3,7 @@ import { listen } from '@tauri-apps/api/event';
 import { invoke } from '@tauri-apps/api/core';
 import { AlertTriangle, CheckCircle2, XCircle } from 'lucide-react';
 import { Button, Card, CardContent, CardHeader, CardTitle } from '@mcpmux/ui';
+import { useNavigateTo } from '@/stores';
 
 /**
  * Incoming approval request emitted by the gateway's ApprovalBroker.
@@ -53,6 +54,7 @@ type Decision = 'allow_once' | 'always_for_this_session_and_client' | 'deny';
 export function MetaToolApprovalDialog() {
   const [queue, setQueue] = useState<ApprovalRequest[]>([]);
   const current = queue[0];
+  const navigateTo = useNavigateTo();
 
   useEffect(() => {
     const unlistenPromise = listen<ApprovalRequest>(
@@ -87,6 +89,16 @@ export function MetaToolApprovalDialog() {
     [current]
   );
 
+  // "Prefer not to be asked?" escape hatch. Deny the current request first —
+  // fail-closed and immediate, so the calling client isn't left hanging for
+  // the full 60s broker timeout — then jump to the Built-in tab, where the
+  // "Require approval for tool changes" switch lets the user turn these
+  // prompts off entirely.
+  const manageApprovals = useCallback(() => {
+    void respond('deny');
+    navigateTo('builtin-servers');
+  }, [respond, navigateTo]);
+
   // Normalize the freeform diff defensively — a missing field must never
   // throw (this previously crashed on `mcpmux_create_feature_set`, whose diff
   // is `{ added_tools }` and has no `after`).
@@ -206,11 +218,22 @@ export function MetaToolApprovalDialog() {
             </Button>
           </div>
 
-          {queue.length > 1 && (
-            <p className="text-[11px] text-[rgb(var(--muted))] text-right pt-1">
-              {queue.length - 1} more pending…
-            </p>
-          )}
+          <div className="flex items-center justify-between gap-3 pt-1">
+            <button
+              type="button"
+              onClick={manageApprovals}
+              className="text-[11px] text-[rgb(var(--muted))] underline-offset-2 hover:text-[rgb(var(--foreground))] hover:underline"
+              title="Deny this request and open the Built-in tab, where you can turn off approval prompts for tool changes"
+              data-testid="meta-tool-approval-manage-link"
+            >
+              Prefer not to be asked? Manage approval prompts →
+            </button>
+            {queue.length > 1 && (
+              <span className="text-[11px] text-[rgb(var(--muted))]">
+                {queue.length - 1} more pending…
+              </span>
+            )}
+          </div>
         </CardContent>
       </Card>
     </div>

tests/ts/components/MetaToolApprovalDialog.test.tsx

@@ -1,16 +1,20 @@
 /**
  * Approval dialog wiring:
- *  - renders the target-Space chip (so a cross-Space write is obvious), and
+ *  - renders the target-Space chip (so a cross-Space write is obvious),
  *  - survives a freeform `diff` shape (`{ added_tools }`) without crashing —
  *    a regression guard for the earlier "Cannot read properties of undefined
- *    (reading 'length')" bug.
+ *    (reading 'length')" bug, and
+ *  - the "Manage approval prompts" link denies the request (fail-closed) and
+ *    routes to the Built-in tab where prompts can be disabled.
  */
 
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { render, screen, act } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
 
-const { handlers } = vi.hoisted(() => ({
+const { handlers, navigateToSpy } = vi.hoisted(() => ({
   handlers: new Map<string, (e: { payload: unknown }) => void>(),
+  navigateToSpy: vi.fn(),
 }));
 
 // Capture the dialog's `listen('meta-tool-approval-request', cb)` so the test
@@ -22,7 +26,9 @@ vi.mock('@tauri-apps/api/event', () => ({
   }),
 }));
 vi.mock('@tauri-apps/api/core', () => ({ invoke: vi.fn().mockResolvedValue(undefined) }));
+vi.mock('@/stores', () => ({ useNavigateTo: () => navigateToSpy }));
 
+import { invoke } from '@tauri-apps/api/core';
 import { MetaToolApprovalDialog } from '@/features/metaTools/MetaToolApprovalDialog';
 
 async function emitRequest(payload: Record<string, unknown>) {
@@ -40,7 +46,11 @@ async function emitRequest(payload: Record<string, unknown>) {
 }
 
 describe('MetaToolApprovalDialog', () => {
-  beforeEach(() => handlers.clear());
+  beforeEach(() => {
+    handlers.clear();
+    navigateToSpy.mockClear();
+    vi.mocked(invoke).mockClear();
+  });
 
   it('names the target Space when present', async () => {
     render(<MetaToolApprovalDialog />);
@@ -82,4 +92,26 @@ describe('MetaToolApprovalDialog', () => {
     expect(screen.getByText(/github_create_issue/)).toBeInTheDocument();
     expect(screen.getByText(/slack_send/)).toBeInTheDocument();
   });
+
+  it('"Manage approval prompts" denies the request and routes to the Built-in tab', async () => {
+    const user = userEvent.setup();
+    render(<MetaToolApprovalDialog />);
+    await emitRequest({
+      tool_name: 'mcpmux_bind_current_workspace',
+      summary: 'Bind this folder',
+      diff: null,
+      raw_args: {},
+      affects_other_clients: false,
+    });
+
+    await user.click(await screen.findByTestId('meta-tool-approval-manage-link'));
+
+    // Fail-closed: the pending request is denied rather than left to time out.
+    expect(invoke).toHaveBeenCalledWith(
+      'respond_to_meta_tool_approval',
+      expect.objectContaining({ decision: 'deny' })
+    );
+    // ...and the user lands on the tab that hosts the approval toggle.
+    expect(navigateToSpy).toHaveBeenCalledWith('builtin-servers');
+  });
 });