Comprehension-Full Fixture

This fixture exercises the full Understanding surface in the canonical v8 post-sidecar shape: the five flat top-level fields (mental_model, purpose, boundary, analogy, misconception) live in SKILL.md frontmatter, and comprehension_state: present lives in the audit-state.json sidecar. The cross-file lint check (per ADR-0019) must accept this pairing — when the sidecar declares comprehension_state: present, the five frontmatter fields are required.

Concept of the skill

What it is: The Understanding surface is the set of five flat frontmatter fields the comprehension grader reads, declared present by the sidecar's comprehension_state flag. Mental model: Two files, one contract — frontmatter holds the teaching prose, the sidecar holds the bookkeeping flag, and a cross-file lint binds them. Why it exists: To prove the post-sidecar split (ADR-0019) keeps the comprehension contract enforceable without the retired nested concept block. What it is NOT: It is not a passing comprehension eval (eval_state) and not routing (routing_eval); presence of the fields is not a quality verdict. Adjacent concepts: the comprehension grader, comprehension_state, the legacy nested concept block. One-line analogy: The flat fields are a book's index; the sidecar flag is the catalog card recording the index exists. Common misconception: That comprehension_state: present means the eval passed — it only means the reading surface exists.