Everforge Mod

Added

• Persistent player presence tracking using NeoForge login and logout events.
• Exact last_login and last_seen timestamps written to everforge/presence/players.json for use by Everforge Admin and member profiles.

Changed

• Release versions are now derived from Git tags instead of being maintained manually in gradle.properties.
• Tagged releases verify that the tag matches vX.Y.Z, the tagged commit is contained in main, the generated JAR filename matches the tag version, and the embedded NeoForge mod version matches as well.