/keel-tidy — the §3.10 sweep: no file left unanswered

When: layout drift is felt (loose files at the repo root, stray one-off scripts, logs/caches in the tree, scratch/ overflowing), at a phase boundary, or every ~5 sessions as hygiene. This is the ritual arm of rules.md §3.10 — "no file of unclear purpose is left in the main source tree". It is NOT /keel-distill's job: distill curates the MEMORY files (§9 caps), tidy curates the FILE TREE (§3 layout) — different axis, different risk, and a file sweep bolted onto a cap rotation would derail both.

1. Sweep — collect candidates deterministically

• Repo-root files outside the discipline scaffold (CLAUDE.md · rules.md · HANDOVER/LESSONS/TASKS/ PLAN · README/LICENSE/CONTRIBUTING · Makefile/pyproject/lockfiles · dotfiles) — §3.10: the root holds scaffold only; application code lives under src/.
• Runtime junk anywhere: *.log · *.tmp · __pycache__/ · .pytest_cache/ · editor swap files · stray outputs sitting outside reports/.
• scratch/ items NOTHING CITES. The criterion is citation, NOT age: a probe named by a reports/ note, ADR or doc is that claim's permanent EVIDENCE (§10.40) and stays put however old it is (field case: a probe untouched for 18 days was the independent measurement behind that week's decision). Check BOTH directions — grep -rl "scratch/<name>" reports/ docs/ *.md for path citations, then grep -rl "<name>" reports/ for the report whose FILENAME carries the id; a path-only check reported a live folder as dead on a real project. Also flag any scratch file missing its 1-line purpose comment (§3.10) — that one IS a per-file check.
• Source files nothing references: not imported (grep the module name across src/ + tests/), absent from Makefile/CI, not collected by the test runner, no docs/architecture.md row.

Off-limits (other jurisdictions): memory files + docs/adr/ (distill / the owner) · reports/ (the §2.8 evidence trail — prune only on an explicit ask) · research/ findings (§8.30) · tests/fixtures/ golden sets (§10.39) · paths already git-ignored.

2. Evidence per candidate — never vibes

One line each: referenced-by (imports / Makefile / CI / docs / reports/ citations) · test-collected? · tracked or untracked · last git touch — recorded LAST and never decisive on its own. A test that LOOKS dead may be a regression fixture guarding a fixed bug (check tests/fixtures/ and the tests-folder README why-lines), and a scratch probe that looks abandoned may be a permanent report's evidence. Watch the grep itself: \b inside grep -E silently matches NOTHING on some platforms — a citation sweep using it returned a clean, plausible, entirely wrong "0 references" (reports/2026-08-18-scratch-layout-audit.md). A zero-reference result is a reason to re-check the instrument before it becomes a delete list (§10.37).

3. Triage table → user approval (nothing moves without it)

• Belongs in the tree → move under src//tests/ + an architecture.md row (§1.6).
• Obsolete + TRACKED → DELETE — git history IS the archive; moving a dead tracked file into an "archive" folder relocates clutter instead of removing it.
• Unsure / maybe-later / UNTRACKED experiment → scratch/archive/<topic>/ with a 1-line purpose header (the §3.10 triad's middle door).
• Runtime junk → delete AND add the PATTERN to .gitignore so the class never returns (§10.39: fix the class, not the instance). Present ONE table — file · evidence · verdict · action. Deletions are their own separately-confirmed list: a blanket "apply all" NEVER covers delete rows — read the delete list back and get an explicit yes on it (per row on request); anything not explicitly confirmed is NOT deleted (it stays, or drops to scratch/archive/ if the user prefers). State recoverability honestly in the table: a tracked delete is restorable (git log --diff-filter=D → git checkout <sha>^ -- <path>); an UNTRACKED delete is gone for good — flag those rows. Apply only approved rows, never silently.

4. Cascade + verify + record

• Cascade every move/delete: grep the old path across *.md (README, docs/, folder READMEs), Makefile, CI — update or remove every reference (§0a cascade discipline).
• make test after moves (imports break silently); hooks/CI still green.
• Record: HANDOVER (a) one-liner (keel-tidy: N moved · M deleted · K ignored), architecture.md rows for moves, and a LESSONS [rule]/[gotcha] line when a junk class earned a .gitignore pattern. Commit with approval (§1.3).