volt: Q139 -- the TOOLS.md drift guard is a fast leg, not a sweep-only cell

checkins/2026-10-31-volt.md

@@ -161,3 +161,36 @@ q136: sandbox FAULT    8 path(s) opened, 0 outside the sandbox,
 - Left alone and disclosed: `--closures` reads
   `/root/.hermes/scripts/troupe_pipe_monitor.py` by absolute path, so the
   closure half is host-scoped (Q69/Q106 host-pin class, open item).
+
+## 2026-10-31 (later still) — Q139 landed: the map drift guard is a fast leg
+
+- Entry, measured at `2e97e4d`: `verify.py --fast` 11 legs / 10 pass / 1
+  skipped, gate OK; `selftest_sweep.py --repo .` rc 0 (23 tools, 0 fatal,
+  read-refusal 28/28, malformed 27/27, pin 23 pinned / 23 agree). Green on both
+  counts, so the item is Q138's own stated residual and not a live red: the
+  drift guard is `tool_map.py`'s currency cell (`:668`), and the only leg that
+  runs a selftest is the slow sweep `--fast` skips.
+- Twelfth leg `tools-map`: `tool_map.py --repo <repo> --rev WORKTREE --check
+  <repo>/docs/TOOLS.md`, 6.0–7.1 s, on every invocation including `--fast`.
+- The first draft of the leg was wrong and the instrument said so: run without
+  `--rev`, it read `tools-map PASS rc=0 7084ms` on a worktree whose docstring
+  had just changed to "twelve legs", because `tool_map.py` defaults to HEAD and
+  HEAD still agreed with the committed document. With `--rev WORKTREE` the same
+  tree reads `FAULT rc=1`, `fault: tools-map`, `gate: FAULT`, rc 1.
+- The pair, measured: pre-render FAULT rc 1 → `--write` → `--check` rc 0 →
+  `tools-map PASS`. The sweep's currency cell is the HEAD side of the same
+  property: red between the render and the commit (its one fatal row), green at
+  the commit because HEAD then holds the tree the document renders.
+- `verify.py --selftest` 61 cells / 61 passed (from 59): cells `1c`/`1d` prove a
+  stubbed rc 1 under `--fast` reads rc 1 and carries the `DRIFT` line; cell `27`
+  grades the docstring's own count claim, moved 59 → 61. Baseline re-pinned by
+  `--write-baseline`: `verify.py\t61\tcells`, 23/23 agree.
+- `docs/TOOLS.md` re-rendered: 7878 B, 23 tools, 12 gate legs; `--check` rc 0.
+  `tool_map.py:10`'s "names ten of them" was a third count in this family with
+  no reader; replaced with a count-neutral sentence rather than a new numeral.
+- Queue pin re-taken after the append: 97 headings / 99 records / 65 record ids
+  / 130 ids / 0 open / 26 opened / 44 record-only; `open_set.py --check` rc 0,
+  selftest 13 cells / 0 failed. `docs/queue-index.md` re-rendered (217 items).
+- Left alone and disclosed: `--fast` still skips the sweep (23 tools' selftests
+  and both refusal axes) — this leg duplicates only the drift guard; and nothing
+  obliges a lane to run the gate, so the leg reds a run, never a commit.