Add framework design docs (model-divergence, rule agents, agent tab)

Design docs in design/framework/ covering:
- Model-divergence enforcement (conflict matrix, modes, auto-assignment)
- Rule Proposer agent (daily scan, proposes rules to RULE_PROPOSALS.md)
- Rule Reviewer agent (monthly consolidation, different LLM than Proposer)
- Agent tab redesign (phase roles + scheduled jobs, remove fake types)
- Schedules, conflict-of-interest, success criteria

Cross-references updated in AGENTS.md, README.md, CHANGELOG.md,
.onboarding.md, prompts/onboarding.md, design/loops/{README,BACKLOG}.md,
memory/v1-1-hardening-session.md.

Also restores scripts/automaton-cleanup.sh stub (was corrupted by
pytest test leak writing temp path into real stub).

design/loops/README.md

@@ -15,6 +15,7 @@ Per-session manual driving doesn't scale against the framework's growing backlog
 - [`functional.md`](functional.md) — what v1 does, roles, the five deaths, blast radius, schedules, success criteria. **Read this first.**
 - [`technical.md`](technical.md) — the implementation contract: file map, `.state.loop` schema, `status.py` flags, gate checks, runner flow, test coverage. **Read this if you're implementing.**
 - [`BACKLOG.md`](BACKLOG.md) — v1.1 and deferred items (Scope 2 design-update loop, Scope 3 self-designing, parallel mode, dashboard panel). The self-improvement loop's work queue.
+- **Sibling design**: [`../framework/`](../framework/) — framework-level agent features (rule agents, Agent tab redesign, model-divergence enforcement). Has its own `BACKLOG.md` consumable via `work_source.area = "framework"`.
 
 ## v1 scope (locked)