ClayGrounds v0.4.5 — DAI 1.9.9 Compatibility

- Updated ClayGrounds from DAI 1.9.5 compatibility to DAI 1.9.9.
- Added explicit stable DAI datapack identity `dai.id = "claygrounds"`.
- Added managed datapack version `dai.version = "0.4.5"`.
- Keeps `dai.role = "main"` so ClayGrounds remains the single main DAI experience.
- DAI 1.9.9 can now identify ClayGrounds independently of the ZIP filename and replace stale world copies with the newest matching global datapack.
- Preserves all v0.4.4 gameplay, articulated entity rigs, native entity identities, combat, progression, worldgen, title screen, UI, and authored map behavior.
- No balance changes or entity presentation redesigns were made in this compatibility pass.
- Pair with ClayGrounds v0.4.5 Resource Pack.
