eliminate per-frame allocations and fix framerate-dependent smoothing

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

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

Refactor cockpit instrument panel to 3D canvas texture, adjust layout, and align ground target heights

Introduce structure registry and fix content loader

Move instrument panel from Three.js canvas texture to DOM canvas overlay

Fix third-person reticle convergence and multiplayer score double-counting

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

refactor: Modularize worldRenderer.ts into AircraftRenderer and HudSyncManager

Refactor worldRenderer.ts by delegating to specialized sub-managers (CameraManager, GroundTargetRenderer, SkyZoneRenderer, HudSyncManager)

Fix invisible bullets and particles by enabling vertexColors on instanced materials and pre-allocating instanceColor attributes

Optimize particle draw calls via InstancedMesh and remove FPV transition shader recompilation lag

Upgrade water to MeshStandardMaterial with animated wave normalMap and smooth shoreline

Invert polygonOffset factors and units for reverse-Z depth support

Use visual groundColor for water and add polygonOffset to prevent water z-fighting over land

Increase camera far plane scale to 1.25 to prevent clipping at the edge of the frustum

Fix terrain z-fighting: reverse landMat polygon offset direction and embed scatter bases

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