- Update hardcoded User-Agent `antigravity/1.11.5` to `1.15.8` in `@mariozechner/pi-ai` via pnpm patch to resolve "version not supported" error.
- Add `sanitizeToolUseInput` helper to ensure `tool_use` payloads include the required `input` field.
- Update `src/infra` usage fetcher User-Agent to match supported version.