Enables gt prime to receive session metadata from LLM runtime hooks.
When called with --hook, reads JSON from stdin containing session_id
and persists it to .runtime/session_id for use by PropulsionNudge.
- Add --hook flag for hook mode
- Parse Claude Code session JSON from stdin
- Support GT_SESSION_ID environment variable fallback
- Persist session ID to .runtime/session_id
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>