Demo log hook
The demo log hook is a minimal post-commit observer that logs every committed Transaction to the console and emits an event on the in-process event bus. It is Phase 1's proof that the hook infrastructure works end-to-end.
What it records
For each committed Transaction:
- Transaction id and submitting agent
- Count of asserts + retracts
- Target Document ids touched
- Gate traversal timing (cheap instrumentation)
Why ship it in Phase 1
- Demonstrability. A visible log during the 6-minute demo makes the registry feel alive, not abstract.
- Verification. The Phase 1 build plan lists "demo hook fires" as a verification step; this hook is what that step asserts against.
- Development ergonomics. While Phase 1 code-at-init hooks evolve, a console log is the fastest feedback loop.
Not in Phase 1
- No persistent audit log (Phase 4 adds an append-only DerivedAuxGraph for transaction history).
- No Slack / email / webhook fan-out (Phase 4 adds the HTTP-webhook transport kind; this hook will remain as the local-only option).