Add schedule promote for atomic cadence promotion

Orchestrates cadence.yml, activity-definitions, fleet schedule.yml,
and activity-core sync in one command. Supports --dry-run and
--fleet-only for repairing partial promotions.

docs/integrations/customer-engagement-playbook.md

@@ -65,7 +65,21 @@ Requires `pip install 'kaizen-agentic[events]'` for `--emit-event`.
 
 ## Cadence promotion
 
-Customer regulator (LOOP-WP-0004) approves promotion. Re-init schedules:
+Customer regulator (LOOP-WP-0004) approves promotion. Use atomic promote to
+align all three layers (cadence.yml, activity-definitions, fleet schedule.yml,
+activity-core sync):
+
+```bash
+kaizen-agentic schedule promote \
+  --engagement-repo /path/to/customer-loop \
+  --engagement <slug> \
+  --to-phase operate \
+  --activity-core /path/to/activity-core
+```
+
+Dry-run: `--dry-run`. Repair fleet drift after a partial promotion: `--fleet-only`.
+
+Legacy per-layer commands still work:
 
 ```bash
 kaizen-agentic schedule init --engagement <slug> --bootstrap-cadence daily --force