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/vscode/CHANGELOG.md

@@ -12,6 +12,7 @@
 - If OpenCode restarts while a response is still running, the chat now stops with an interrupted state and a notification to continue instead of hanging silently (thanks to @sum117).
 - Usage: Z.ai credit limits now appear alongside its other quota windows.
 - Chat: file paths in messages now open from the session's workspace, even if you last browsed files in another workspace (thanks to @tomzx).
+- Chat: app links such as `spotify://` now ask for confirmation before opening another app. You can trust an app link type on one device and manage trusted links in Settings.
 - While a reply streams, the model status line under the last message now turns into the finished message's info row in place, instead of jumping when the reply completes.
 - Chat: newly sent messages and syntax-highlighted code blocks no longer briefly flicker. Bash output can also grow with its content instead of being cut off.
 - Chat: long user messages can be expanded even when their final layout finishes after they first appear.