Delivered: 提升 @gravito/core 開發者體驗 — 修正 API footgun、強化型別安全、收斂公開 API、同步文件與 CI lint 強化

Key accomplishments:
- Router stdout 清理 + ModelNotFoundException typed exception
- 6 star exports → named exports; setApp 從公開 barrel 移除
- ApplicationConfig extends Pick<GravitoConfig>; Container.make() ServiceMap overload
- Biome noExplicitAny error + noConsole + publint CI gate (57 packages)
- README API 同步、orbit/register/use 決策指南、JSDoc 英文統一

See .planning/MILESTONES.md for full details.