MP-ADMIN-ADMINISTRATIVE-0813-CLOSURE-PREFLIGHT-001: make exact closure recovery unstarvable

[fyremael]

Successor execution repair under open control issue #554.

Protected observation after #559:

• the exact Aug13 recovery classifier is live-valid against current protected GitHub state;
• a post-MP-ADMIN-ADMINISTRATIVE-0813-EXECUTOR-BINDING-REPAIR-001: restore closure reachability #559 scheduled candidate workflow executed from protected 8381fb2345b7d226064f0d9cce12e73be2c7a584 and successfully refreshed [maintenance-candidate] structural_sweep due 2026-08-18T13:21:00Z #561/[maintenance-candidate] deep_conformance_review due 2026-08-19T01:21:00Z #557;
• nevertheless no Aug13 receipt branch materialized;
• candidate preparation is therefore not the blocker;
• the remaining runtime boundary is the BEHIND/full-executor preamble before the exact protected closure recovery becomes observable.

This PR makes only the already-authorized exact Aug13 closure path structurally first inside the existing single Referee/executor step. Candidate preparation and runtime-contract validation remain in their ordinary positions. The Referee/executor step then runs an exact-target-only preflight before administrative_autonomy_runtime.py execute.

The preflight imports the protected runtime overlay chain, asks the existing pending_closures classifier for the exact #475/#476 tuple, and, only when that exact tuple is the sole target, delegates unchanged to existing finish_closure mechanics. If the exact target is absent, it is a no-op and the ordinary runtime executes as before. If recovery completes, the step exits before the ordinary runtime so the checkout that predates the protected receipt merge is not reused.

The existing single-use github.token Referee credential remains exactly once in the workflow; Candidate/Referee/administrator separation and permissions are unchanged.

Scope:

• issue [maintenance-candidate] administrative_review due 2026-08-13T01:21:00Z #475 / merged PR [maintenance-final] MP-ADMIN-ADMINISTRATIVE-REVIEW-2026-08-13-001 #476 only;
• occurrence administrative_review:2026-08-13T01:21:00Z only;
• record MP-ADMIN-ADMINISTRATIVE-REVIEW-2026-08-13-001 only;
• no completion-ledger edit in this PR;
• no record re-execution or re-merge;
• no [maintenance-receipt] MP-ADMIN-ADMINISTRATIVE-REVIEW-2026-08-16-001 #558 mutation or merge;
• no ordinary candidate finalization authority in the preflight;
• no generalized closure recovery, cadence/deadline reset, structural-frontier mutation, bypass/direct protected push, or substantive claim authority.

The regression suite proves exact-target identity rejection, no-target/no-authority behavior, unchanged finish_closure delegation, runtime-overlay import ordering, preflight-before-full-runtime ordering, single-use Referee token preservation, and mandatory reachability through the existing administrative validation module.

Control-plane admission requires fresh exact-head machine gates, independent non-author exact-head APPROVED review, explicit Human Steward exact-head disposition, expected-head protected merge, and protected-main readback.

Refs #554, #555, #559, #475, #476, #558.

[gcl-release-trust]

Advisory visual status report — PRVSR-LIVE-PR562-78a2a8d43a5b-20260818082711

• operative state: UNKNOWN
• freshness: CURRENT
• exact PR head: 78a2a8d43a5b4c02b949be51516188de6ba2fe60
• source snapshot SHA-256: 000648aceaec3b81aa6fdc9166591b38742178958ec6d330fb0cea98682c5ae3
• durable archive: governance/pr_visual_status_archive/grandchallenge/MATH-PROGRAMME/pr-562/PRVSR-LIVE-PR562-78a2a8d43a5b-20260818082711/

This is a deterministic, derived, advisory presentation of governed source state. It does not create review, authorization, merge, certification, or propagation authority. The target PR head was not modified by archive or transport generation.

Phase 1 archive branch: prvsr-advisory-archive/pr-562
Archive path: governance/pr_visual_status_archive/grandchallenge/MATH-PROGRAMME/pr-562/PRVSR-LIVE-PR562-78a2a8d43a5b-20260818082711/
Report generation or archive failure remains advisory and non-blocking.

[fyremael]

EXACT-HEAD REVIEW CHECKPOINT

PR #562 is review-ready at exact head 78a2a8d43a5b4c02b949be51516188de6ba2fe60 against protected base 8381fb2345b7d226064f0d9cce12e73be2c7a584.

All 16 pull-request workflow lanes are terminal SUCCESS on this exact head, including:

• Administrative maintenance automation validation 32115287079;
• Programme policy checks 32115287041 (administrative and repository-regression shards green);
• GCL conformance 32115287682;
• Administrative maintenance dispatcher 32115287116;
• the full triggered CMDG pinned replay matrix.

Scope remains five files only. The patch leaves candidate preparation and credential separation unchanged, preserves exactly one ${{ github.token }} Referee binding, and inserts an exact-target-only Aug13 closure preflight inside the existing Referee/executor step before the BEHIND/full-runtime path. The preflight can recover only issue #475 / merged PR #476 / record MP-ADMIN-ADMINISTRATIVE-REVIEW-2026-08-13-001; if absent it is a no-op, and if protected completion succeeds the stale checkout is not reused by the ordinary executor.

No completion-ledger edit, record re-execution/re-merge, #558 mutation/merge, generalized closure recovery, cadence/deadline reset, structural-frontier mutation, bypass/direct protected push, or substantive claim authority.

There are no unresolved review threads. The prior jimsteeg review on superseded head e3f6ddd7... is dismissed and creates no authority. Fresh independent non-author APPROVED review must bind exactly 78a2a8d43a5b4c02b949be51516188de6ba2fe60 before any Human Steward disposition or protected merge.