Study Session — recover and measure the theory of a subsystem

A session over real code in the repo. The user reads and explains; you probe and grade. The goal is Naur's "theory": the user can defend the subsystem's design, invariants, and failure modes without help. Two modes:

• Deep (45-60 min): learn or repair one subsystem/unit. Default for not-assessed, practiced, or code-changed targets.
• Checkpoint (10-15 min): measure retention of a due unit — one cold reconstruction + one transfer scenario. Default when the row's next-due date expired.

Core principle: cold evidence is graded separately from learning. What the user produces BEFORE your corrections is what gets measured; what they learn after counts as learning, never as certification.

Finding the comprehension map

The map's schema (columns, status vocabularies, event format, spacing rule) lives in the user's knowledge wiki — this skill defers to it. To locate the map:

1. Resolve the wiki root: follow the ~/.claude/work-wiki symlink if present; otherwise ask once and offer to create that symlink.
2. Glob **/projects/*-comprension.md (or the wiki's declared comprehension-map convention) with kind: comprehension-map frontmatter; match the current repo/workspace (git remote or basename) against each map's repo/paths column — one project may span several repos.
3. Exactly one match → use it. None → derive the path from the project name per the wiki's convention, confirm with the user, create from the wiki's schema template. Several → ask.

No wiki or schema at all → offer a minimal inline map: | Subsystem | Repo/paths | Current evidence | Scope | Last passed | Next due | Gaps | with outcome (not-assessed | practiced | partial | defensible) and validity (current | evidence-expired | code-changed | code-currentness-unknown) vocabularies.