test(rest): route the picker e2e stub engine's update/delete through the dispatch predicates (#7467)

check:engine-double-contract flagged the new stub: a fake looser than
ObjectQL's update/delete is how #4434 shipped a dead route green. Both
verbs now open with assertEngineUpdateDispatch/assertEngineDeleteDispatch
from @objectstack/metadata-core (#5619).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CnMk7vfrt2zW7xvwLS3JDf

Author: claude

packages/rest/src/public-form-lookup-picker.test.ts

@@ -26,6 +26,10 @@
  * conversion chain is a different seam, untouched by this card.
  */
 import { describe, expect, it, vi } from 'vitest';
+// The engine-double contract (#4434 / #5619): a fake engine's update/delete
+// must be exactly as strict as ObjectQL's dispatch, or a dead route ships with
+// its suite green. Both predicates live in metadata-core.
+import { assertEngineDeleteDispatch, assertEngineUpdateDispatch } from '@objectstack/metadata-core';
 import { ObjectStackProtocolImplementation } from '@objectstack/metadata-protocol';
 import { RestServer } from './rest-server';
 
@@ -46,8 +50,14 @@ function stubEngine() {
                 rows.push({ id: `r_${nextId}`, ...data });
                 return { id: `r_${nextId}` };
             },
-            async update() { return { id: null }; },
-            async delete() { return { deleted: 0 }; },
+            async update(_t: string, data: Record<string, unknown>, opts: { where: Record<string, unknown> }) {
+                assertEngineUpdateDispatch(data, opts);
+                return { id: null };
+            },
+            async delete(_t: string, opts: { where: Record<string, unknown> }) {
+                assertEngineDeleteDispatch(opts);
+                return { deleted: 0 };
+            },
             registry: { registerItem: () => {}, registerObject: () => {}, listItems: () => [] },
         } as any,
     };