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/integrations/kaizen-schedule-prepared-event.md

@@ -0,0 +1,90 @@
+# Event Payload: `kaizen.schedule.prepared`
+
+**Status:** design — for **future event-driven runs**. v1 of WP-0006 is
+cron-driven (activity-core fires the schedule). This event lets a runner or
+activity-core react when a `schedule prepare` bundle has been assembled, without
+polling.
+
+kaizen-agentic does **not** publish this event today; the `prepare` command
+writes to stdout. This spec fixes the contract so an emitter (a runner wrapper
+or a thin `--emit` flag in a later iteration) and consumers agree on the shape.
+
+## Subject
+
+```
+kaizen.schedule.prepared
+```
+
+NATS/event-bus subject, sibling to the existing `kaizen.metrics.recorded` and
+`kaizen.agent.installed` subjects (Pattern 2).
+
+## Payload
+
+```json
+{
+  "event": "kaizen.schedule.prepared",
+  "version": "1",
+  "occurred_at": "2026-06-17T09:00:12Z",
+  "repo": "kaizen-agentic",
+  "root": "/home/worsch/kaizen-agentic",
+  "agent": "coach",
+  "cadence": "weekly",
+  "prepare_command": "kaizen-agentic schedule prepare coach --target /home/worsch/kaizen-agentic",
+  "bundle": {
+    "format": "markdown",
+    "agent_prompt_found": true,
+    "has_memory": true,
+    "has_metrics": true,
+    "pointers": ["scope", "todo"],
+    "bytes": 8421
+  },
+  "session_close": [
+    "kaizen-agentic metrics record coach --success --time <s> --quality <0-1>"
+  ]
+}
+```
+
+### Fields
+
+| Field | Type | Notes |
+|-------|------|-------|
+| `event` | string | Always `kaizen.schedule.prepared` |
+| `version` | string | Payload schema version |
+| `occurred_at` | RFC3339 | When the bundle was assembled |
+| `repo` | string | State Hub slug |
+| `root` | string | Absolute checkout path |
+| `agent` | string | Agent the bundle orients |
+| `cadence` | string | `daily` \| `weekly` \| `monthly` |
+| `prepare_command` | string | Exact CLI that produced the bundle |
+| `bundle.format` | string | `markdown` \| `json` |
+| `bundle.agent_prompt_found` | bool | Mirrors `schedule prepare --format json` |
+| `bundle.has_memory` | bool | Memory file present |
+| `bundle.has_metrics` | bool | Metrics summary present |
+| `bundle.pointers` | string[] | Repo pointer labels found (`scope`, `todo`) |
+| `bundle.bytes` | int | Rendered bundle size |
+| `session_close` | string[] | Suggested close commands |
+
+The `bundle.*` flags map 1:1 to the JSON output of
+`kaizen-agentic schedule prepare <agent> --format json`, so an emitter can build
+this payload from the existing command without new computation.
+
+## Consumers (illustrative)
+
+- **activity-core** — close the loop: mark the scheduled task `in_progress` when
+  a bundle is prepared.
+- **artifact-store** — archive large bundles by reference.
+- **dashboards** — fleet view of which scheduled runs have been prepared vs.
+  executed.
+
+## Boundary
+
+- The payload carries **metadata and a command**, never secrets or full repo
+  contents.
+- kaizen-agentic owns the schema; emission wiring (NATS publish) is a future
+  iteration and belongs to the runner / activity-core integration.
+
+## Related
+
+- [discover-kaizen-scheduled-repos.md](discover-kaizen-scheduled-repos.md)
+- [INTEGRATION_PATTERNS.md Pattern 2](../INTEGRATION_PATTERNS.md)
+- [ADR-005](../adr/ADR-005-scheduled-agent-execution.md)