KithMoot desktop 0.1.70

Messages stay visible after Send. The newest queued message is brought into view immediately, with its sending state, and accepted messages appear without waiting for the relay to echo them. A pending row stays until the chat shows its message. Retries keep the same signed event.

Also includes the room/Dock unread and roster-control fixes from 0.1.69. Mac is Developer ID signed and notarised; Linux x64/ARM64 tarballs and Debian packages are included. Windows x64 remains an unsigned preview.