Replace prompt-based skill approach with OpenClaw lifecycle hooks
(before_agent_start, agent_end, before_compaction, before_reset).
State injection now happens automatically at the hook level,
making it model-agnostic and reliable across all providers.
- Add index.js with 5 lifecycle hooks
- Add openclaw.plugin.json manifest
- Rewrite post-install.sh to handle plugin installation
- Update README with plugin architecture docs
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
