fix snapshot payload mismatch crashing multiplayer onMessage handler

feat: integrate Google Earth 3D Tiles and optimize engine hooks

Add unit tests for client-side multiplayer listeners and register them in package.json

Implement terrain, map coordinate, and GLB collision upgrades, configure WebSockets keepalive, and fix client MapSchema callbacks TypeError

Add comprehensive unit tests for MultiplayerRoom and fix client MapSchema callbacks TypeError

Defer Colyseus schema listeners until state.players is defined to fix undefined crash on join

Add client-side error reporting and diagnostics endpoint

Refactor to server-authoritative multiplayer with 60Hz CSP and Colyseus