docs(gate): stop check-engine-double-contract restating its own ledger size in prose

The pinned ledger is a generated artifact: `--write` — the action the gate's
own failure messages instruct authors to take — moves its row count, and seven
prose sites in this file had copied that count beside it. Five were already
wrong (308/319 against a live 310/321), and one derived claim ("11 pairs carry
more than one") was never right: 11 is the EXCESS of doubles over rows, while
the number of rows pinning more than one is 10, as the paragraph 40 lines below
already said.

Each site is now either silent about the magnitude or resting on a claim the
ratchets themselves guarantee (pinned is grow-only, the baseline shrink-only,
so "already outnumbers" and "hundreds" cannot go stale). The two sites that
state a genuinely un-derivable measurement are anchored as dated, past ones.

Comment-only: no invariant, criterion, exit code, population or output string
is touched.

Part of #9915

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XqDQYVU5smx29ts9pAErja

Author: claude

scripts/check-engine-double-contract.mjs

@@ -203,17 +203,21 @@
 //
 // Method, stated so this can be redone rather than trusted: membership is
 // proxied by `assertEngine…Dispatch(` call sites in test files under the scan
-// roots, calibrated against this gate's own ledger at HEAD -- 0 false negatives
-// on the file sets, and 309 of 310 (file, verb) rows agreeing on the exact
-// count. Anyone re-running it must first prove their clone actually covers the
-// window; a shallow one silently answers for its own depth, which is the whole
-// reason this paragraph had to be rewritten.
+// roots, calibrated on 2026-08-19 against this gate's own ledger as it then
+// stood -- 0 false negatives on the file sets, and every (file, verb) row but
+// ONE agreeing on the exact count. That calibration is a dated measurement, not
+// a standing property; anyone re-running it must first prove their clone covers
+// the window; a shallow one silently answers for its own depth, which is the
+// whole reason this paragraph had to be rewritten.
 //
 // So the additions the ratchet does redden on are already in conversation with
 // this gate (they are new fakes that had to write `assert…Dispatch` because
-// PINNED demanded it). 310 entries today against the 135 the DEBT ledger
-// already carries: same file format, same order of magnitude, same
-// reconciliation shape.
+// PINNED demanded it). Set against the DEBT ledger this gate already carries,
+// the pinned ledger is the same file format, the same order of magnitude and
+// the same reconciliation shape -- so it is the maintenance cost already being
+// paid for the other ledger, not a new one. Both sizes are printed by a run and
+// countable in the artifacts; they are deliberately not copied into this prose,
+// because `--write` moves one of them and nothing here would notice.
 //
 // ## How a LEGITIMATE decrease is expressed (the anti-nuisance half)
 //
@@ -1476,10 +1480,12 @@ function readBaseline() {
  * The RETAINED ledger (#9680) — the enumerated pinned population.
  *
  * Deliberately a SEPARATE artifact from `engine-double-contract.baseline.json`
- * rather than more rows in it. The baseline is 135 hand-written MEASURED
+ * rather than more rows in it. The baseline is a set of hand-written MEASURED
  * justifications whose readability this file's header calls the gate's whole
- * value ("shrink-only, hand reviewed"); folding 308 generated rows in would
- * bury the reasons under the census and blur which rows a human must agree to.
+ * value ("shrink-only, hand reviewed"); folding the generated rows in would
+ * bury the reasons under a census that ALREADY OUTNUMBERS them -- and, by the
+ * opposite polarities below, can only outnumber them further -- blurring which
+ * rows a human must agree to.
  * These two ledgers also answer to opposite polarities — the baseline records
  * debt and may only SHRINK, this one records coverage and may only GROW — so a
  * reader who conflates them reads every ratchet in this file backwards.
@@ -1497,10 +1503,11 @@ function readPinnedLedger() {
  * diff.
  *
  * Counted per FILE and not merely as membership, because a file may hold more
- * than one pinned double for a verb — measured on this branch: 319 pinned
- * doubles across 308 (file, verb) pairs, so 11 pairs carry more than one. A
- * membership-only ledger would let a file that pins two deletes drop to one in
- * silence, which is this card's defect at a finer grain.
+ * than one pinned double for a verb — the rows reading `"pinned"` above 1 in
+ * `engine-double-contract.pinned.json` are the live list, and the ledger is
+ * where to read how many there are rather than here. A membership-only ledger
+ * would let a file that pins two deletes drop to one in silence, which is this
+ * card's defect at a finer grain.
  */
 function censusPinned(slices) {
   const rows = [];
@@ -1537,7 +1544,8 @@ const pairKey = (file, verb) => JSON.stringify([file, verb]);
  * remedy attached to the wrong story.
  *
  * Counted rather than a membership Set, because a file may pin several doubles
- * for one verb (measured: 10 of 308 rows do). Membership alone cannot separate
+ * for one verb (the ledger rows reading `"pinned"` above 1 are the live list,
+ * as above). Membership alone cannot separate
  * "the file pinned two deletes and now pins one because a MEMBER WAS DELETED"
  * from "...because a member stopped calling the predicate", and those two want
  * opposite remedies: restore the member vs re-pin it.
@@ -1578,8 +1586,9 @@ const REGEN = 'node scripts/check-engine-double-contract.mjs --write';
 function retainedErrors(census, ledger, ledgerExists, declared, onDisk) {
   const errors = [];
 
-  // Bootstrap. Without this a missing artifact reports 308 separate "not in the
-  // ledger" errors, which reads as a catastrophe and buries the one-line fix.
+  // Bootstrap. Without this a missing artifact reports one "not in the ledger"
+  // error per census row -- hundreds of them, and growing, since this ledger is
+  // grow-only -- which reads as a catastrophe and buries the one-line fix.
   if (!ledgerExists) {
     return [
       `RETAINED: ${relative(ROOT, PINNED_LEDGER_PATH)} is missing. That file IS the pinned `
@@ -2915,7 +2924,8 @@ class Svc {
     grewMore.length === 1 && anyOf(grewMore, 'Coverage grew'));
 
   // ── Bootstrap: a missing ledger is ONE error, not one per row. The failure
-  // this guards is a fresh checkout reporting 308 problems for one missing file.
+  // this guards is a fresh checkout reporting one problem per census row for a
+  // single missing file.
   const missing = retainedErrors(
     [{ file: 'a.test.ts', verb: 'delete', pinned: 1 }, { file: 'b.test.ts', verb: 'update', pinned: 1 }],
     { entries: [] }, false, dcount([]), onDisk);