Modern GPUs have 8-16GB VRAM - leverage this to cache all M2 models permanently.
Changes:
- Disabled cleanupUnusedModels() call when tiles unload
- Models now stay in VRAM after initial load, even when tiles unload
- Increased taxi mounting delay from 3s to 5s for more precache time
- Added logging: M2 model count, instance count, and GPU upload duration
- Added debug logging when M2 models are uploaded per tile
This fixes the "building pops up then pause" issue - models were being:
1. Loaded when tile loads
2. Unloaded when tile unloads (behind taxi)
3. Re-loaded when flying through again (causing hitch)
Now models persist in VRAM permanently (few hundred MB for typical session).
First pass loads to VRAM, subsequent passes are instant.
5cfb13f714