test(rest): the new pin imports with an explicit .js extension (#9232)

`check:type-check-debt --re-measure` reported @objectstack/rest's TEST_DEBT at
156 against a frozen 155: TS2835, this package resolves `nodenext` and the new
file's relative import had no extension. The neighbouring suites omit it and are
part of that frozen pile; a new file must not add to a shrink-only ratchet, and
raising the entry is maintainer-only and not a way to get CI green.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: claude

packages/rest/src/rest-thrown-code-vocabulary.test.ts

@@ -51,7 +51,11 @@
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import { ErrorCode, standardErrorCodeForHttpStatus } from '@objectstack/spec/api';
 import { INTERNAL_ERROR_MESSAGE } from '@objectstack/types';
-import { mapDataError, sendThrownError, sendDeclaredFault } from './error-response';
+// `.js` extension deliberately: this package resolves `nodenext`, so an
+// extensionless relative import is a `tsc` error (TS2835). The neighbouring
+// suites omit it and are part of this package's frozen TEST_DEBT — a new file
+// must not add to a shrink-only ratchet.
+import { mapDataError, sendThrownError, sendDeclaredFault } from './error-response.js';
 
 // ---------------------------------------------------------------------------
 // Vehicles