Add Fand platform support

[MC20018]

Summary

Adds a MiniMOTD platform implementation for Fand.

This introduces:

• minimotd-fand platform module
• Fand plugin descriptor generation via io.fand.plugin
• /minimotd command support for help, about, and reload
• Fand ServerListPingEvent integration for MOTD, player count, player hover list, hidden player count, and server icon
• server list status refresh after MiniMOTD reload
• README entry for Fand in the supported server platforms list

Verification

Ran successfully:

./gradlew.bat :minimotd-fand:spotlessJavaCheck :minimotd-fand:checkstyleMain :minimotd-fand:build --console=plain --no-daemon --max-workers=1

Result:

BUILD SUCCESSFUL