chore(scripts): record the new REST findOne double in the pinned ledger

`check:engine-double-contract` named it: the cached-ETag door pin declares a
findOne double the pinned ledger does not record, so the ledger would not
protect that file. Written by the gate's own `--write`, which reports 0
seams added, grown or lost.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XTBcV7zZHmokdyQgXjbyEU

Author: claude

scripts/engine-double-contract.pinned.json

@@ -3266,6 +3266,11 @@
       "verb": "update",
       "pinned": 1
     },
+    {
+      "file": "packages/rest/src/rest-server-meta-cached-etag-door-scope.test.ts",
+      "verb": "findOne",
+      "pinned": 1
+    },
     {
       "file": "packages/rest/src/rest-server-meta-history-diff-org-scope.test.ts",
       "verb": "delete",