ZNPCsPlus 2.1.0 manual_map.1

Fork release with Maven migration and runtime fixes.

Included fixes:

• Maven build + CI migration
• SnakeYAML classloading fix
• Async NPC spawn/despawn event scheduling fix
• PacketEvents secure-chat guard for old server versions
• Additional tests and README fork notes

Assets:

• ZNPCsPlus-2.1.0-manual_map-a224abb.jar
• SHA256SUMS.txt