docs: add Contents blocks to the seven reference spokes over 300 lines that check 26 flags

[kyle-sexton]

Summary

skill-quality:check 0.22.0 (PR #4069) adds check 26: a markdown file under a skill's reference/, references/, or context/ directory, at any depth, over 300 lines with no table of contents in its first 40 lines gets an advisory WARN. The threshold restates Anthropic's progressive disclosure guidance (a long reference file opens with a table of contents so the model can jump instead of scanning), verified 2026-09-10. A fleet sweep on main at 18c85c25f flags seven spokes.

Files

Skill	Spoke	Lines
plugins/claude-config/skills/audit-pass	reference/run-state-and-resumability.md	310
plugins/claude-ops/skills/observability	context/data-sources.md	380
plugins/claude-ops/skills/plugins	context/gotchas.md	321
plugins/claude-ops/skills/plugins	context/scope-semantics.md	431
plugins/overengineering/skills/audit	context/surface-walk.md	311
plugins/source-control/skills/setup	reference/apply-convention.md	421
plugins/writing/skills/be-concise	reference/sources.md	321

Scope

• Add a ## Contents block near the top of each file listing its section anchors (three or more in-page anchor links inside the first 40 lines clears the check). The two existing skill-authoring spokes and skill-quality/check/reference/fresh-eyes-declarations.md show the shape.
• Where a file is long because it holds two unrelated topics, splitting it into two spokes is an acceptable alternative; the hub must then reference both (check 15).
• Bump each touched plugin's patch version and CHANGELOG per check-changelog-parity.sh.
• Verify with bash plugins/skill-quality/scripts/check-skill.sh <skill> showing no check 26 WARN, and markdownlint-cli2 clean.

Related

• Origin: deferred follow-up from feat(skill-quality,playbooks): apply Anthropic's skill-authoring best practices as checks, guidance, and recorded deviations #4069, left for the owning plugins rather than widening that PR.