fix(ui): open app deep links from chat after confirmation (#2932)

* fix(ui): open app deep links from chat after confirmation

DOMPurify's default URI policy stripped href from anchors with custom
application schemes (obsidian://, vscode://, ...), so every app link
rendered in chat was dead across web, desktop, VS Code, and mobile.

- Classify safe app-link schemes in lib/url.ts (browser-handled,
  scriptable, webview-internal, network, and self-deep-link schemes
  stay excluded) and let openExternalUrl accept them
- Keep app-link hrefs through the markdown sanitize hook
- Intercept app-link clicks in the markdown renderer and route them
  through a confirmation dialog (Trust and open / Open once, dismiss
  to cancel) mounted in the desktop/web app root and the mobile shell
- Persist per-device trusted schemes in a zustand store; trusted
  schemes open without asking again

* feat(settings): manage trusted app link schemes in General

Add an App links section to Settings > General listing the application
schemes trusted on this device with a delete action; removing a scheme
restores the confirmation dialog for it. Register the section in
settings search.

* fix(ui): enforce app link confirmation

* fix(ui): handle app links by runtime

* fix(vscode): keep app links unsupported

* fix(settings): clarify trusted app links

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/components/chat/AppLinkConfirmDialog.test.tsx

@@ -0,0 +1,46 @@
+import React from 'react';
+import { beforeEach, describe, expect, mock, test } from 'bun:test';
+import { renderToStaticMarkup } from 'react-dom/server';
+
+import { I18nProvider } from '@/lib/i18n';
+
+mock.module('@/components/ui/dialog', () => ({
+  Dialog: ({ children }: React.PropsWithChildren) => <>{children}</>,
+  DialogContent: ({ children }: React.PropsWithChildren) => <div>{children}</div>,
+  DialogDescription: ({ children }: React.PropsWithChildren) => <p>{children}</p>,
+  DialogFooter: ({ children }: React.PropsWithChildren) => <div>{children}</div>,
+  DialogHeader: ({ children }: React.PropsWithChildren) => <div>{children}</div>,
+  DialogTitle: ({ children }: React.PropsWithChildren) => <h2>{children}</h2>,
+}));
+
+const { AppLinkConfirmDialog } = await import('./AppLinkConfirmDialog');
+const {
+  getAppLinkConfirmationSnapshot,
+  openAppLinkWithConfirmation,
+  settleAppLinkConfirmation,
+} = await import('./appLinkConfirmation');
+
+describe('AppLinkConfirmDialog', () => {
+  beforeEach(() => {
+    if (getAppLinkConfirmationSnapshot()) {
+      settleAppLinkConfirmation('cancel');
+    }
+  });
+
+  test('keeps cancel visible and focused beside both open choices', () => {
+    void openAppLinkWithConfirmation('obsidian://open?vault=Notebook');
+
+    const markup = renderToStaticMarkup(
+      <I18nProvider>
+        <AppLinkConfirmDialog />
+      </I18nProvider>,
+    );
+
+    expect(markup).toContain('>Cancel</button>');
+    expect(markup).toContain('autofocus=""');
+    expect(markup).toContain('>Open once</button>');
+    expect(markup).toContain('>Trust and open</button>');
+
+    settleAppLinkConfirmation('cancel');
+  });
+});