Features:
- Add Antigravity Provider for Google internal Gemini 3 Pro API
- Add dynamic route support (/:selector/v1/messages)
- Add protocol converter for Antigravity
- Add protocol selector for smart conversion path
Improvements:
- Add pre-commit hooks for local lint/format checks
- Simplify CI to only build check (lint moved to pre-commit)
- Update frontend with Antigravity support
Breaking Changes:
- Route parameter syntax changed from {param} to :param for Axum 0.7