test(good-fences): show which mower the neighbor gets

The chat and load arrows drew `things: { mower }` whether I lent the
raw mower or the governed one. Name objects by the reply arrow that
introduced them, so the diagram reads `things: { mower: governed }`
and lending the raw mower would fail the trace comparison.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

good-fences/test/lend-the-mower.test.ts

@@ -31,14 +31,23 @@ const tipsyTenant = `(env) => {
   return 'mowed 20 cells';
 }`;
 
-/** `{ a, b: { c } }`: keys, and the keys of object-valued members */
-const shape = (record: Readonly<Record<string, unknown>>) =>
+/** diagram-local names, bound by the reply arrows that introduce them */
+const local = new WeakMap<object, string>();
+const bind = (name: string) => (result: unknown) => {
+  local.set(result as object, name);
+  return name;
+};
+
+/** `{ a, b: { c: governed } }`: keys, nested objects by their keys, and
+ * objects with a diagram-local name by that name */
+const shape = (record: object): string =>
   `{ ${Object.entries(record)
-    .map(([key, value]) =>
-      value !== null && typeof value === 'object' && !Array.isArray(value)
-        ? `${key}: { ${Object.keys(value).join(', ')} }`
-        : key,
-    )
+    .map(([key, value]) => {
+      if (value === null || typeof value !== 'object') return key;
+      const name = local.get(value);
+      if (name) return `${key}: ${name}`;
+      return Array.isArray(value) ? key : `${key}: ${shape(value)}`;
+    })
     .join(', ')} }`;
 
 const quoted = (result: unknown) => `'${String(result)}'`;
@@ -50,19 +59,22 @@ const viz = harden({
       return `lend({ webkey: '${webkey}', limit: ${limit}, say })`;
     },
   },
-  mower: { result: () => 'mower' },
-  govern: { args: args => `mower, ${String(args[1])}`, result: () => 'governed' },
+  mower: { result: bind('mower') },
+  govern: {
+    args: args => `${local.get(args[0] as object)}, ${String(args[1])}`,
+    result: bind('governed'),
+  },
   chat: {
-    label: args => `chat(${shape(args[0] as Record<string, unknown>)})`,
+    label: args => `chat(${shape(args[0] as object)})`,
     result: quoted,
   },
   complete: {
     label: args =>
-      `complete([${(args[0] as Record<string, unknown>[]).map(shape).join(', ')}])`,
+      `complete([${(args[0] as object[]).map(shape).join(', ')}])`,
     result: () => 'code',
   },
   load: {
-    args: args => `code, { ${Object.keys(args[1] as object).join(', ')} }`,
+    args: args => `code, ${shape(args[1] as object)}`,
     result: () => 'tenant',
   },
   run: { result: quoted },