docs(runbook): weekly drain sequence — PROPOSE mode + AUTO-flip criteria

[akaszubski]

Summary

Document the weekly autonomous drain sequence (PROPOSE mode + falsifiable AUTO-flip criteria) in RUNBOOK.md to establish governance for continuous-improvement draining and direction-guard metrics.

Implementation Approach

Modify docs/RUNBOOK.md periodic-aggregation section:

1. Subsection "Weekly Drain Sequence (PROPOSE mode)": /triage --auto-improvement → top cluster → /implement --issues <cluster> → /improve --auto-file → bash scripts/deploy-all.sh (MANDATORY final step) → digest review
2. PROPOSE mode (ships now): human triggers weekly, reviews ONE digest. No plugin scheduling dependency (/schedule is optional harness-level capability)
3. AUTO-flip criteria (all falsifiable, ALL must be true): M0: Durable pipeline state isolation — per-run UUID, atomic ownership, crash-safe handoff #1041 closed AND [CI-critical] [INCOMPLETE] plan-critic/spec-validator/CIA skipped across drain pipelines — FORBIDDEN lists have no hook backing under .bypass #1195 closed AND 2 consecutive PROPOSE drains with zero .claude/.bypass events AND deploy-all.sh validation exit 0
4. Direction guards enumerated: PROJECT.md alignment gate unchanged (/implement STEP 2); worktree isolation; nothing merges on red; digest metrics (open auto-improvement count trend, recurrence-after-close rate, test count trend, deploy validation pass rate, .bypass event count with alarm if >0)
5. Cross-reference from [umbrella] Add periodic-aggregation passes to mirror per-event automations #1075 periodic-aggregation pattern

Acceptance Criteria

• Full PROPOSE-mode sequence documented in RUNBOOK.md
• AUTO-flip criteria listed verbatim and falsifiable
• deploy-all.sh documented as mandatory final step; validation exit code is digest metric AND AUTO-flip prerequisite
• All 5 direction-guard metrics enumerated
• Cross-referenced from periodic-aggregation section ([umbrella] Add periodic-aggregation passes to mirror per-event automations #1075)

Part of macro-first plan (.claude/plans/macro-first-continuous-improvement.md). Docs-only; suitable for /implement --light.
Plugin Version: 3.50.0 (c41558b)