Fold six maintainer review signals into the skill

Adds six rules that review rounds corrected and no linter holds: the docs standard over older sibling pages, naming a third-party project, where customer docs live, which docs paths skip writer review, reading CODEOWNERS before naming a group, and owning the pipeline after final approval. just ci passes (vale parity, sims-check, word-budget 45519 of 46000). Body additions only, no restructure, so the fidelity test is not required.