Desktop mode's focus gating (from #49) made losing OS focus send "leave"
for every open room, which stopped live message delivery to that room,
not just notification eligibility -- so a message wouldn't render until
the room was manually left and rejoined. Room join/leave is now gated on
visibility alone, matching the browser; notification eligibility gets its
own separate signal (a "focus"/"blur" WS frame tracked by a new
Redis-backed FocusPresence), so a connected-but-unfocused desktop member
still gets notified without losing live delivery.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Offline members now also get a desktop_notification WS envelope
alongside the existing Web Push send, since Electron has no push
delivery service configured. The client only acts on it when
window.dsDesktop is present and the user's local preference allows it,
so the server needs no awareness of which clients are Electron.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
ksmithandClaude Sonnet 5