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).
- The VNC client refuses desktop sizes over 64 Mpx (ServerInit and
DesktopSize/ExtendedDesktopSize) and ZRLE rectangles over 64 MiB before
allocating, so a hostile server can't force a multi-gigabyte allocation.
- Release URLs from the update manifest and repository URLs from the GitHub
API are handed to the system opener only when they are http(s) links.
- SSH key pairs are generated with ssh-key (Ed25519/ECDSA P-256/RSA) and
encrypted in-process, so the passphrase no longer appears as an ssh-keygen
command-line argument visible in the process list.
- open_tunnel's loopback bridge checks the accepted peer is our own client
socket, so a local process racing for the ephemeral port can't be spliced
into the IRC/VNC SSH tunnel.
- run_command caps buffered output at 1 MiB; local-forward abort handles are
pruned as connections finish; SOCKS5 host/credential lengths over 255 bytes
are rejected instead of being truncated into a malformed request.