test(metadata-protocol): hold the caller's limit in the fanout find double; ledger the new pinned engine doubles

check:objectql-double-limit named the new find double limit-blind — the
bound now applies after the filter, by presence. The engine-double ledger
learned the fanout file's pinned delete/findOne/update doubles via the
gate's own --write.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Q5WBDtaUnoz5XuJ6jk8pQ5

Author: claude

packages/metadata-protocol/src/protocol.cluster-mutation-fanout.test.ts

@@ -138,12 +138,17 @@ function makeReplica(store: ReturnType<typeof makeSharedStore>) {
             if (table !== 'sys_metadata') return null;
             return findRow(opts.where)?.row ?? null;
         },
-        async find(table: string, opts?: { where?: Record<string, unknown> }) {
+        async find(table: string, opts?: { where?: Record<string, unknown>; limit?: number }) {
+            // Hold the caller's bound AFTER the filter, by PRESENCE — the
+            // objectql-double-limit contract: a bound the double ignores makes
+            // a pagination bug invisible to every test built on it.
+            const bound = <T>(all: T[]): T[] =>
+                typeof opts?.limit === 'number' ? all.slice(0, opts.limit) : all;
             if (table === 'sys_metadata_history') {
-                return historyRows.filter((h) => matchesHistory(h, opts?.where ?? {}));
+                return bound(historyRows.filter((h) => matchesHistory(h, opts?.where ?? {})));
             }
             if (table !== 'sys_metadata') return [];
-            return Array.from(rows.values()).filter((r) => matchesWhere(r, opts?.where ?? {}));
+            return bound(Array.from(rows.values()).filter((r) => matchesWhere(r, opts?.where ?? {})));
         },
         async insert(table: string, data: Record<string, unknown>) {
             if (table === 'sys_metadata_audit') return { id: 'audit_skip' };

scripts/engine-double-contract.pinned.json

@@ -351,6 +351,21 @@
       "verb": "update",
       "pinned": 1
     },
+    {
+      "file": "packages/metadata-protocol/src/protocol.cluster-mutation-fanout.test.ts",
+      "verb": "delete",
+      "pinned": 1
+    },
+    {
+      "file": "packages/metadata-protocol/src/protocol.cluster-mutation-fanout.test.ts",
+      "verb": "findOne",
+      "pinned": 1
+    },
+    {
+      "file": "packages/metadata-protocol/src/protocol.cluster-mutation-fanout.test.ts",
+      "verb": "update",
+      "pinned": 1
+    },
     {
       "file": "packages/metadata-protocol/src/protocol.code-only-types.test.ts",
       "verb": "delete",