Instead of wiring encrypted crew chat into the global notification bell — which
would mean background-decrypting every crew's messages to power a badge (slow,
battery-hungry, unreliable with NIP-17's random timestamps) — add a subtle
unread dot to the crew's own Chat tab.
- useCrewChatUnread: member-only, single-crew, runs only while the crew page is
open. Uses a pure metadata query (newest Cordn envelope by created_at, no
decryption) vs. the local last-seen timestamp. For the built-in NIP-17
transport (random timestamps, needs decryption) it deliberately returns false
rather than fire false pings — the in-chat "New" divider already covers
"what did I miss" once the tab is opened.
- Tabs made controlled; the dot is suppressed while the Chat tab is active, so
it clears the moment you look, and is gone on the next visit (last-seen
advances). No global notification noise.
Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>
