explain-changelisted

# Change rationale explanation ## Purpose Explain the implementation without overstating evidence or owning another stage. ## When to use Use after review closeout or for a direct rationale request. Direct requests remain isolated. ## Inputs and evidence Resolve the actual diff first. Read the smallest decision-bearing proposal, spec, test spec, design, plan, review, tests, and validation evidence. Distinguish observed, inferred, and unknown facts. Flag unrelated changes, non-goals, risks, sensitive data, and evidence gaps; never explain from memory. Resolve paths from the request, active metadata, project guidance, then the portable default. Portable durable output requires one exact path and never creates governed state. Use `change.yaml` for current state and treat the plan and upstream artifacts as read-only. ## Generated Markdown readability Write normal Markdown paragraphs with stable IDs. Do not split a sentence across physical source lines. Diagrams are optional. Do not require manual-proof contracts from readability alone. ## Classification and resources Classify the governed signal as `no-governed-signal`, `single-governed-candidate`, or `invalid-or-ambiguous-governed-signal`. A malformed, duplicated, escaped, unsafe, stale, missing-root, mismatched, or conflicting signal stops without portable fallback. Independently select `inline-explanation`, `create-durable-explanation`, or `refresh-durable-explanation`. Create requires an exact absent target. Refr