fix(devx): pin test-typecheck debt by error IDENTITY, not per-file count

The EXACT ratchet in scripts/check-test-typecheck.mts recorded ONE INTEGER
per file. An integer measures a quantity, never an identity, so a file's
entire error population could rotate underneath a constant number and the
gate printed OK.

Measured by ablation in packages/rest, not argued (#13470): src/rest.test.ts
was recorded at 2, PR #13466 replaced both hand-built IHttpRequest literals
with a typed builder, and it measured 2 again -- while NEITHER error was the
same error. tsc reports at most ONE argument-assignability error per call, so
the request literals had been MASKING response-literal errors at the very same
two call sites; repairing the request unmasked the response one line down.

A ledger entry is now a map of normalized error SIGNATURE to count. A
signature is the TS code plus the diagnostic message with churn-prone spans
collapsed, and it carries NO line or column -- so unrelated edits above an
error do not touch the ledger, and only a change to WHICH error is present
does. Both halves of the set difference are named: which signature ARRIVED
and which VANISHED.

Counts are provably unmoved by the migration: rest 1 file / 2 errors, spec
54 files / 262 errors, identical before and after.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pk26oZ12t5N1hwGW1m1MgC

Author: claude

packages/rest/test-typecheck-debt.json

@@ -1,7 +1,9 @@
 {
-  "_comment": "Per-file tsc error debt of the @objectstack/rest TEST layer (#5286). `tsconfig.test.json` compiles `src/**/*.test.ts` — which `tsconfig.json` excludes and therefore no gate ever read — and every file below still carries errors from before that gate existed. THIS FIELD IS GENERATED: every regeneration rewrites it from scripts/check-test-typecheck.mts, and the EXACT ratchet below requires a regeneration on every repair — so an edit made here is gone by the next one. Anything true of THIS package goes in the sibling `_note` field, which is authored, is preserved verbatim, and is never written by the generator (#12624). This comment states NO cause for the errors, deliberately: the classes differ per package and per file, they move as the debt is paid down, and a cause written here is rewritten verbatim into every ledger by every regeneration — so it outlives its own repair and cannot be corrected in the file where it is read. Measure instead, before repairing anything: `tsc --noEmit --pretty false -p tsconfig.test.json` in the package prints the real classes with their TS codes. EXACT ratchet, judged by re-running tsc: a file that gains errors is red, a file that loses them is red until its number is re-recorded, a file that reaches zero is red until its entry is deleted, and a file NOT listed here may have no errors at all. Regenerate with: pnpm --filter @objectstack/rest gen:test-typecheck-debt",
-  "_note": "Everything still recorded here is held by its own card, and none of it is an annotation repair. #13454 holds the one entry that remains: src/rest.test.ts's two hand-built IHttpResponse literals, which omit the send and header members that interface requires and whose status is not typed as returning the interface, so res.status(...).json(...) does not chain. WARNING, and the reason this note exists: the count did NOT move when #13377 landed, but the errors underneath it were replaced wholesale. This file was recorded at 2 before that card and measures 2 after, and neither of the two is the same error. tsc reports at most ONE argument-assignability error per call expression, so the request literals #13377 removed had been masking these response literals at the very same two call sites. Read that as the warning an EXACT ledger cannot give you itself: a per-file count measures a QUANTITY, never an identity, and a constant number is not evidence that nothing changed. The request literals #13377 held are gone from this package: the five members IHttpRequest requires are stated once, in src/http-request-test-builder.ts, and a request built there takes its method and its path from the route under test instead of from a default, so the two cannot disagree. The exceljs call that #13378 held is likewise no longer here: that dependency declares its own module-local Buffer, which shadows Node's inside every exceljs signature, so no Node Buffer can be passed to Workbook.xlsx.load - the assertion that costs is stated once, in src/xlsx-test-loader.ts, and every xlsx-reading test in this package goes through it.",
+  "_comment": "Per-file tsc error debt of the @objectstack/rest TEST layer (#5286). `tsconfig.test.json` compiles `src/**/*.test.ts` — which `tsconfig.json` excludes and therefore no gate ever read — and every file below still carries errors from before that gate existed. THIS FIELD IS GENERATED: every regeneration rewrites it from scripts/check-test-typecheck.mts, and the EXACT ratchet below requires a regeneration on every repair — so an edit made here is gone by the next one. Anything true of THIS package goes in the sibling `_note` field, which is authored, is preserved verbatim, and is never written by the generator (#12624). This comment states NO cause for the errors, deliberately: the classes differ per package and per file, they move as the debt is paid down, and a cause written here is rewritten verbatim into every ledger by every regeneration — so it outlives its own repair and cannot be corrected in the file where it is read. Measure instead, before repairing anything: `tsc --noEmit --pretty false -p tsconfig.test.json` in the package prints the real classes with their TS codes. Each entry maps a file to its per-SIGNATURE error counts, never to a bare total (#13470): a signature is the TS code plus the diagnostic message with structural type blobs collapsed, and it carries NO line or column — so the pin survives edits that move code around, and only stops matching when the error itself becomes a different error. EXACT ratchet, judged by re-running tsc: a file that gains errors is red, a file that loses them is red until its number is re-recorded, a file that reaches zero is red until its entry is deleted, a signature that ARRIVES or VANISHES is red even when the file total is unchanged, and a file NOT listed here may have no errors at all. Regenerate with: pnpm --filter @objectstack/rest gen:test-typecheck-debt",
+  "_note": "Everything still recorded here is held by its own card, and none of it is an annotation repair. #13454 holds the one entry that remains: src/rest.test.ts's two hand-built IHttpResponse literals, which omit the send and header members that interface requires and whose status is not typed as returning the interface, so res.status(...).json(...) does not chain. WARNING, and the reason this note exists: the count did NOT move when #13377 landed, but the errors underneath it were replaced wholesale. This file was recorded at 2 before that card and measures 2 after, and neither of the two is the same error. tsc reports at most ONE argument-assignability error per call expression, so the request literals #13377 removed had been masking these response literals at the very same two call sites. That blindness is now CLOSED (#13470): an entry is no longer one integer but a map of normalized error SIGNATURE to count, so this file pins WHICH errors it carries and not merely how many, and the very substitution described above now reds with the signature that ARRIVED and the one that VANISHED both named. The history is kept because the mechanism is not rest-specific and has not gone away: tsc still reports at most one argument error per call, so a repair here can still uncover a different error at the same site. What changed is that the signature keys below - never their sum - are what say so. The request literals #13377 held are gone from this package: the five members IHttpRequest requires are stated once, in src/http-request-test-builder.ts, and a request built there takes its method and its path from the route under test instead of from a default, so the two cannot disagree. The exceljs call that #13378 held is likewise no longer here: that dependency declares its own module-local Buffer, which shadows Node's inside every exceljs signature, so no Node Buffer can be passed to Workbook.xlsx.load - the assertion that costs is stated once, in src/xlsx-test-loader.ts, and every xlsx-reading test in this package goes through it.",
   "entries": {
-    "src/rest.test.ts": 2
+    "src/rest.test.ts": {
+      "TS2345: Argument of type '…' is not assignable to parameter of type 'IHttpResponse'.": 2
+    }
   }
 }