feat: scheduled agent execution via activity-core (WP-0006, v1.3.0)

Enable kaizen agents to run on a regular cadence against a preselected repo
roster, orchestrated by activity-core and prepared by kaizen-agentic — without
this repo owning cron, Temporal workers, or an LLM runtime.

CLI + module:
- src/kaizen_agentic/schedule.py — .kaizen/schedule.yml parse/validate/scaffold
- `kaizen-agentic schedule` group: init, validate, list, prepare <agent>
  (prepare bundles agent prompt + memory + metrics + repo pointers, offline)
- tests/test_schedule_cli.py — 15 tests

Contract & design:
- ADR-005 scheduled agent execution; schema doc + example manifest
- discover_kaizen_scheduled_repos resolver spec, state-hub roster fields,
  kaizen.schedule.prepared event payload, activity-core handoff checklist
- INTEGRATION_PATTERNS Pattern 2 extended with roster model

ActivityDefinition drafts (enabled: false):
- weekly-coach-orientation, weekly-optimization-review

Docs: agency-framework, CLI cheat sheet, PACKAGE_RELEASE runner prereqs,
EcosystemIntegration, CHANGELOG, TODO. Workplan closed (status: done).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/CLI_CHEAT_SHEET.md

@@ -88,6 +88,22 @@ kaizen-agentic memory init tdd-workflow --no-metrics   # memory only
 
 Session-close template: `docs/templates/session-close-protocol.md`
 
+### Scheduled Agent Execution (ADR-005)
+```bash
+# Opt this repo into fleet scheduling
+kaizen-agentic schedule init                  # coach + optimization weekly
+kaizen-agentic schedule init --timezone UTC   # override timezone
+kaizen-agentic schedule validate              # schema + agent-name checks
+kaizen-agentic schedule list                  # enabled entries (--all incl. disabled)
+
+# Prepare orientation for a scheduled run (offline; no State Hub needed)
+kaizen-agentic schedule prepare coach                 # markdown bundle
+kaizen-agentic schedule prepare optimization --format json
+```
+
+activity-core fires the schedule and creates a task per (repo, agent); the task
+runs `schedule prepare`. kaizen-agentic does not run cron or invoke Claude.
+
 ### Information
 ```bash
 # List templates