---

kind: infra

Extend the figure-text opaque-code detector to digit-prefixed rung/condition slugs

Provenance

Surfaced by the clean-result-critic at #2479 clean-result gate round 2 (epm:clean-result-critique v2, 2026-08-24T15:36:57Z), and independently corroborated by the codex-clean-result-critic twin the same round (epm:clean-result-critique-codex v2, finding opaque-ladder-figure-labels).

workflow_fix_target: scripts/verify_task_body.py (figure-text opaque-code check)

Problem

verify_task_body.py's figure-text opaque-code check did not flag digit-prefixed condition/rung slugs rendered as axis tick labels inside a committed figure. At #2479 the figure figures/issue_2479/ladder_curves.png carried the tick labels 1_direct, 2_ctx_offset, 3_ans_offset, 4_bias_refit, 5_global_scale, 6_rotation, 7_ctx_reparam, 8_ans_reparam, 9_full_AMB, with AMB glossed nowhere in the body. The mechanical pre-pass returned OVERALL: PASS on that body; both LM reviewers caught it by eye.

The standing rule is that opaque condition codes never reach reader-facing surfaces, figures included, and the project already has the plain-English form in the sibling figure rungwise_ordering.png (relabelled at commit f23b6d8bdb).

Two properties made this class invisible to the existing detector:

1. The label is a <digit>_<slug> compound, so patterns anchored on a leading letter or on a bare-slug shape miss it.
2. The string lives in the figure's rendered tick labels and its meta.json sidecar, not in body prose, so a body-prose-only scan cannot see it. The sidecar IS greppable: git show <pin>:figures/issue_2479/ladder_curves.meta.json contains every offending token.

Why it matters

The gap is latent until a figure moves from footer-only provenance into an embedded reader-facing position, which is exactly what happened here: closing one lens gap (embedding the per-unit companion) opened this one, and only the LM lenses caught it. A mechanical detector would have caught it at draft time in both positions.

Scope

1. Extend the figure-text opaque-code check to the <digit>_<slug> compound form.
2. Have the check read the committed figure meta.json sidecars for embedded figures, not body prose alone, so tick-label text is in scope.
3. Fixture-test both shapes against the #2479 artifacts: ladder_curves.meta.json at pin fd4e118f3aa7feccb1ab994e829f5bb46069469e must FAIL, and rungwise_ordering.meta.json at the same pin must PASS.

Acceptance criteria

• A body embedding a figure whose sidecar carries digit-prefixed condition slugs FAILs the check with the offending tokens named.
• The plain-English sibling figure still PASSes (no false positive).
• Regression tests cover both fixtures.
• No change to the existing body-prose opaque-code behavior.