Aster Bridge 0.4.28

feat(macos): native app menu, status item, window state, notifications

Add macOS menu bar with standard app, edit, view, window, and help menus,
template status-item icon with live bridge status, Dock icon removal when
the window closes, window size and position memory, native notifications
for failed sends and updates, About panel and Finder metadata, and quit
that drains the outbox first. Bump to 0.4.28. Release workflow now
publishes as prerelease and promotes to latest only after all fixed-name
download assets exist.