Better WebConsole

Performance and packaging

• Reduced final plugin jar size by excluding unused JNA native binaries for unsupported/rare platforms.
• Removed extra Maven/package metadata from shaded jars.
• Optimized WebSocket broadcasts so stats/log JSON payloads are built once per broadcast instead of once per connected client.
• Reduced small runtime allocations in stats collection, API request body reading, log export filtering, and player/reason validation.