Survival stats, HUD mockup, Guardian retexture, build opts
- Skip DDS conversion if texture has not changed
- Add survival stats to Player: HP, mana, hunger, thirst, energy
- Serialize/deserialize Player survival stats to/from JSON
- Add HUD mockup with survival stats icon
- Add HP, mana, and stats icon assets
- Add ProgressBar node stub
- Retexture and re-rig Crystal Sanctuary Guardian
- Make backward movement speed 2x slower
- Fix Node3d saveJson to call Node::saveJson
- Fix rsync target path for Windows build