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/App.tsx

@@ -1,6 +1,7 @@
 import React from 'react';
 import { MainLayout } from '@/components/layout/MainLayout';
 import { ChatView } from '@/components/views/ChatView';
+import { AppLinkConfirmDialog } from '@/components/chat/AppLinkConfirmDialog';
 import { FireworksProvider } from '@/contexts/FireworksContext';
 import { Toaster } from '@/components/ui/sonner';
 import { Button } from '@/components/ui/button';
@@ -908,6 +909,7 @@ function App({ apis }: AppProps) {
                   isVSCodeRuntime={isVSCodeRuntime}
                   embeddedBackgroundWorkEnabled={embeddedBackgroundWorkEnabled}
                 />
+                <AppLinkConfirmDialog />
               </div>
             </TooltipProvider>
           </RuntimeAPIProvider>
@@ -951,6 +953,7 @@ function App({ apis }: AppProps) {
                   <OpenCodeUpdateToast />
                   <MainLayout />
                   <Toaster />
+                  <AppLinkConfirmDialog />
                   {!isBootShell && (
                     <>
                       <ConfigUpdateOverlay />