Max Weinbach6/17/2026, 5:44:34 PM

Extract desktop app logic out of the sources-carousel AI Elements primitive:
- Drop confirmAction (desktopCommands) and the app CitationSource type; the
  primitive now takes a local SourceItem[] and an onOpenSource(url) callback
- Add src/lib/openExternalSource.ts (confirm -> window.open) as the call-site
  behavior, wired in FeedRow via onOpenSource
- Split the test: pure component asserts onOpenSource is called; helper test
  asserts confirm -> window.open (and the cancel path)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Parent80865aa