GTR089.1 — Repair invalid <help> RST (partition fix)

Contract: render-equivalence (proof by execution).

Claim

The repair changes nothing but the docutils error.

Proof — by execution, per tool

A repaired round is kept only when it strictly reduces serious docutils messages, adds no new error class, and leaves the doctree structurally identical modulo the removed system messages (tier-1 rst, xml §23). The gate vetoes e.g. the trailing-transition fix (renders an <hr>). Macro-bearing and format="markdown" help skipped.