Design rationale

Leading words: code is not intent, coverage map, Direct Supported Inferred Speculative Unknown.

Companion to subsystem-walkthrough. That skill is runtime. This one is the forces that produced the shape.

Copy these steps into the todo list verbatim. Skip with skip: <reason>.

Parse the target and the question. If vague, state your guess and proceed.
Code-anchor: paths, symbols, git blame / git log --follow, PR numbers, gh pr view when gh exists.
Coverage map of seven categories. Spawn one investigator per category that exists. Document the null; do not skip the search silently.
Synthesize with references/epistemics.md. Keep confidence language intact.
Present. If this investigation precedes a change, add Preserve / Change / Avoid / Risk.

design-rationale