feat: engagement CLI for forward-deployed agency (WP-0009 T08)

Add kaizen-agentic engagement subcommands (list, show, validate, checklist,
phase, prepare, staff, quote, scrub, export-handoff) backed by engagement.py
for file-based pilot lifecycle. Tests cover staff/validate/phase/prepare and
the railiance01 pilot smoke path.

CHANGELOG.md

@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   `keepaTodofile` agent remains available for other projects
 
 ### Added
+- **`engagement` CLI (WP-0009 T08)** — forward-deployed engagement lifecycle:
+  `list`/`show`/`validate`/`checklist`/`phase`/`prepare`/`staff`/`quote`/
+  `scrub`/`export-handoff` over file-based pilots (`engagements/pilots/`)
 - **`metrics record --emit-event`** — publishes `kaizen.metrics.recorded` NATS
   envelope for activity-core event-driven definitions (optional `nats-py` via
   `pip install 'kaizen-agentic[events]'`)