test(metadata-protocol): the harness find double honours the caller's limit

check:objectql-double-limit refuses a NEW limit-blind double ('the baseline
never grows'): the copied harness answered more rows than the real engine
would, so every assertion downstream of it measured a shape production never
produces. Applies the bound after the filter, by presence.

Records the new file's engine doubles in the pinned ledger, as
check:engine-double-contract prescribes for new pinned coverage.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012zGPuVVX3deAx9LdjK8jCk

Author: os-try2026

packages/metadata-protocol/src/protocol-publish-drafts-object-field-refs.test.ts

@@ -130,11 +130,15 @@ function makeStubEngine() {
             }
             return findRow(opts.where)?.row ?? null;
         },
-        async find(table: string, opts: { where: Record<string, unknown> }) {
-            if (table === 'sys_metadata_history') {
-                return historyRows.filter((h) => matchesHistory(h, opts.where));
-            }
-            return Array.from(rows.values()).filter((r) => matchesMetadataWhere(r, opts.where));
+        async find(table: string, opts: { where: Record<string, unknown>; limit?: number }) {
+            const matched = table === 'sys_metadata_history'
+                ? historyRows.filter((h) => matchesHistory(h, opts.where))
+                : Array.from(rows.values()).filter((r) => matchesMetadataWhere(r, opts.where));
+            // The caller's bound, applied AFTER the filter and by PRESENCE — a
+            // double that silently ignores `limit` answers more rows than the
+            // real engine would, and every assertion downstream of it is then
+            // measuring a shape production never produces.
+            return typeof opts?.limit === 'number' ? matched.slice(0, opts.limit) : matched;
         },
         async insert(table: string, data: Record<string, unknown>) {
             if (table === 'sys_metadata_audit') return { id: 'audit_skip' };

scripts/engine-double-contract.pinned.json

@@ -161,6 +161,21 @@
       "verb": "update",
       "pinned": 1
     },
+    {
+      "file": "packages/metadata-protocol/src/protocol-publish-drafts-object-field-refs.test.ts",
+      "verb": "delete",
+      "pinned": 1
+    },
+    {
+      "file": "packages/metadata-protocol/src/protocol-publish-drafts-object-field-refs.test.ts",
+      "verb": "findOne",
+      "pinned": 1
+    },
+    {
+      "file": "packages/metadata-protocol/src/protocol-publish-drafts-object-field-refs.test.ts",
+      "verb": "update",
+      "pinned": 1
+    },
     {
       "file": "packages/metadata-protocol/src/protocol-publish-drafts-org-scope.test.ts",
       "verb": "delete",