## Problem
The session-PR-scope guardrail shipped as a PreToolUse hook
(`hooks/session-pr-counter.sh`, PR #362), but **PR #511 (the 3.0
hookless teardown) deleted all hooks**. Six workflow-discipline surfaces
were never updated — they still advertise the hook as a live, shipping
mechanism. That's a **stale active-surface promise + a lost reliability
guardrail** (surfaced by the ag-4hf7 Google-SRE audit:
"explainability/trust" turned inward).
## Hookless re-enforcement (the decision)
- **The mandatory layer already survives**: the `/evolve` post-mortem
checkpoint #6 (council-gated, cannot be bypassed) enforces session-scope
for autonomous loops — the actual failure mode. It only lacked a
canonical count source.
- **New `scripts/session-pr-scope.sh`** — the reusable hookless count +
verdict (`OK`/`WARN`/`BLOCK`), fail-open, robot-friendly
(`--json`/`--count`). It is now:
- the checkpoint's `$session_pr_count` source, and
- the one-liner an **opt-in** hook wraps (re-author via the
hooks-authoring skill — AgentOps ships none).
- 8 bats cases (thresholds, block-mode exit code, fail-open); shellcheck
clean.
## Stale-doc truth (6 surfaces, all hedged)
CLAUDE.md · AGENTS-WORKFLOW.md · skills/ship-loop/SKILL.md · the evolve
postmortem-checkpoint (skills/, skills-codex/, packs overlay — kept in
parity; codex hashes regenerated for **evolve + ship-loop only**, the 7
pre-existing drifts left untouched).
## Ratchet (knowledge → a constraint)
Extend `check-hookless-cold-start.sh` to cover these workflow-discipline
surfaces — reversing the now-stale CLAUDE.md carve-out — so this exact
drift class **cannot recur**. Gate scope 5 → 10 surfaces; its bats test
stays green. (This is the "knowledge becomes a constraint" invariant the
whole ag-4hf7 thread identified as our edge — applied to the very gap
that thread surfaced.)
## Verification
- `bats tests/scripts/session-pr-scope.bats` → 8/8
- `bash scripts/check-hookless-cold-start.sh` → PASS (10 surfaces)
- `check-hookless-cold-start.bats` → 5/5 ·
`validate-codex-generated-artifacts.sh --scope head` → pass ·
wiring-closure → pass · shellcheck clean · overlay ≡ source
Closes-scenario: ag-o5xp#session-pr-scope
Bounded-context: BC3-Loop
Evidence: scripts/session-pr-scope.sh
Bo