The aggregate chat unread badge used two different definitions: web/
desktop's sidebar summed unread messages while mobile's tab badge (and
the since-removed ChatFab badge it mirrored) counted sessions — the same
account state showed e.g. 5 on web and 2 on iOS. The sidebar also summed
ALL sessions while the thread list zeroes the row being viewed, so a
reply landing in the open conversation flashed a sidebar count with no
matching row.
- packages/core/chat/unread.ts: countUnreadChatMessages() as the single
shared definition (IM-style message total, optional viewed-session
exclusion); pure so mobile can import it.
- app-sidebar: use the helper and exclude the actively-viewed session,
but only while a chat surface is actually showing it (chat route or
floating window open) — a remembered selection with both surfaces
closed still counts, since nothing will auto mark-read there.
- mobile: tab badge switches to the shared message count (99+ cap like
the sidebar), ChatSessionSchema parses unread_count, and markRead's
optimistic patch zeroes unread_count alongside has_unread.
Co-authored-by: Lambda <lambda@multica.ai>
Co-authored-by: multica-agent <github@multica.ai>
