A page that keeps one Codeman window open, such as a task board, could only
show a session by sending that window to /session/<id>, which loads the whole
app again for every click. The dashboard now reads a #session=<id> fragment
when it loads and on hashchange, selects that session, and removes the
fragment with history.replaceState so the next identical link is still a
change. Re-pointing a window that already shows the dashboard changes only the
fragment, so the page stays loaded and the switch is a tab change.
A link can name a session the dashboard does not list yet, because the page
that created it may link before session:created arrives. The id waits until
that event names it, and picking another tab yourself retires it.
Following a link is an app selection (`auto: true`). The page that set the
fragment may be a script, so it must not spend the session's idle alert.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
