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/INTEGRATION_PATTERNS.md

@@ -73,6 +73,45 @@ test -f .kaizen/metrics/optimizer/analysis.json && echo OK
 
 **Boundary:** kaizen-agentic does not run Temporal schedules.
 
+### Scheduled agent execution (WP-0006, ADR-005)
+
+Beyond the metrics-only definitions above, agents themselves run on a cadence
+against a **preselected repo roster**. The roster combines three sources:
+
+| Source | Purpose |
+|--------|---------|
+| State Hub `GET /repos/` | Canonical slug list + `host_paths` |
+| Repo opt-in: `.kaizen/schedule.yml` exists with `version` set | Per-repo enablement |
+| Optional hub flag `kaizen_schedule_enabled: true` (future) | Operator override |
+
+A repo is **schedule-eligible** when it is registered with reachable
+`host_paths` **and** carries a valid `.kaizen/schedule.yml`. The activity-core
+resolver `discover_kaizen_scheduled_repos` intersects these and emits
+`context.scheduled_runs` (one entry per `(repo, agent)`); definitions `for_each`
+over that output.
+
+| Definition | Trigger | Agent | Prepare command |
+|------------|---------|-------|-----------------|
+| [weekly-coach-orientation](integrations/activity-definitions/weekly-coach-orientation.md) | Cron Mon 09:00 | `coach` | `schedule prepare coach` |
+| [weekly-optimization-review](integrations/activity-definitions/weekly-optimization-review.md) | Cron Mon 10:00 | `optimization` | `schedule prepare optimization` |
+
+**Listing schedule-eligible repos** (operator, no activity-core code):
+
+```bash
+# In each candidate repo on a host listed in state-hub host_paths:
+kaizen-agentic schedule validate && kaizen-agentic schedule list
+```
+
+**Design docs (no state-hub / activity-core code in this repo):**
+
+- [schedule-schema.md](integrations/schedule-schema.md) — `.kaizen/schedule.yml`
+- [state-hub-roster-fields.md](integrations/state-hub-roster-fields.md) — hub fields/filters
+- [discover-kaizen-scheduled-repos.md](integrations/discover-kaizen-scheduled-repos.md) — resolver spec
+- [kaizen-schedule-prepared-event.md](integrations/kaizen-schedule-prepared-event.md) — event payload
+
+**Boundary:** kaizen-agentic declares and prepares; activity-core schedules;
+state-hub owns the roster.
+
 ---
 
 ## Pattern 3 — artifact-store evidence retention