Every shared lock was std::sync::Mutex with lock().unwrap() (~150 sites),
so a panic in any session's reader or callback poisoned the lock and the
next UI frame panicked too, dropping every open session. Locks are now
parking_lot::Mutex (no poisoning; already in the dependency tree), and a
panic hook reports worker panics as an error toast instead of the session
silently stopping (F3, F4).
Under the 'ask' policy a changed host key used to be a hard error. The
prompt now shows the stored and received fingerprints and offers Reject,
Accept Once (connect, keep the record) and Accept & Update (replace the
record; audited). Unknown keys gain an Accept Once option too. Strict and
accept-new still refuse changed keys without prompting. Known-host rows
written by the old app are confirmed removable by id (test).
The NickServ password (and any other "remember for this session" secret) was
resolved through a fresh per-connect cache, so every auto-reconnect prompted
again with a 60 s timeout and an unanswered prompt failed the reconnect.
Session-only secrets now live on the session, survive auto and explicit
reconnects, and IDENTIFY is sent on every registration as before.
Andy Dixon