v0.92

Security-hardening release.

• --password (or explicit --no-password) is now required, so a forgotten flag fails loudly instead of silently exposing an open server.
• WebSocket handshakes validate the Origin header, blocking cross-origin CSRF against signed-in players.
• Sign-in form opts out of password-manager autofill — usernames/passwords here aren't stable credentials and shouldn't be captured.
• Readme: added a warning about save-file overwrite/listing in the launch directory.