feat: /zulip-test command + standardized health schema v1
- Added /zulip-test self-test command (7 checks: queue, identity,
@all-bots, health, poll loop, echo prevention, API send)
- Standardized health endpoint to zulip-health/v1 schema
(nested zulip{} object, checks{} map, platform/agent metadata)
- Saved pi extension source to pi-zulip-extension/extension-src/
(with all fixes: dynamic @all-bots, health sync, logging)
- Added extension src to repo for deployment tracking
- Updated vault with final contract status report
Abiba (pi)
2f6c4283d2