feat: initial release v0.1.0

- Shadow Army agents (monarch, beru, igris, bellion, tusk, tank, shadow-sovereign)
- Custom tools for shadow delegation (arise_summon, arise_background, etc.)
- Hooks (arise-banner, output-shaper, compaction-preserver, todo-enforcer)
- CLI installer (bunx opencode-arise install)
- Configuration system with project/global config support
- CI/CD with GitHub Actions