Improve Galaxy XR setup, tracking capabilities and settings

[AngelDark92]

Summary

• Publish Steam Link hand/eye/face capabilities while preserving sharing and OSC preferences.
• Install managed driver copies, restore journaled SteamVR settings on uninstall, and preserve the bundle for reinstalling.
• Fix readiness checks and settings reload races; keep App Settings available after uninstall.
• Reorganize Driver Settings, Image Settings and Distortion Profile, enable Native Identity by default, and gate advanced/image controls. Remove obsolete UI components.
• Add backed-up legacy identity cleanup under About and backend/native/UI regression coverage.

Validation

Local validation passed: 40 Rust tests, 21 service fixtures, 12 Angular UI tests, and native/GUI release builds. Live SteamVR/headset verification remains pending.