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

Add client-side error reporting and diagnostics endpoint

Fix lobby online count and multiplayer bot crash

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

Introduce structure registry and fix content loader

Add WebRTC DataChannels with Metered TURN for HF deployment sync

Fix stall physics, tracer visibility, net packet size, and type modularization

Refactor codebase to under 150 lines per file; reduce FPV turbulence and adjust cockpit scaling