Gyro: versions and changes

The bundle now declares native hook points (hooks: 3), so the launcher builds it on any Horizon with native hook API v3 or newer instead of only the pinned commit.

• Deterministic packaging: identical sources give identical bytes and SHA-256; tools/package.py --check-hooks cross-checks the pinned commit's real API.
• Mod row (id, version, description) now comes from runtime.rs constants.
• Added proof.py, an in-game proof harness driving the modded client on throwaway data folders.
• Player-facing README rewrite.

Client-side camera and player-model changes only; no network writes and no server component.