feat: show Role and Usage/Quota columns on the Accounts list

Created At is replaced with two columns that previously required
opening each account individually: Role (badge, resolved against
x:UserRoles specifically since the list's merged User/Group field
definitions otherwise resolve `roles` against the wrong object) and
Usage / Quota (usedDiskQuota vs quotas.maxDiskQuota, "Unlimited" when
no limit is set).

Also makes renderCellValue's generic 'object' case resolve variant
labels via schema.schemas, instead of only ever printing the raw
@type string.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/lib/accountColumns.ts

@@ -0,0 +1,34 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <hello@stalw.art>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+import type { Schema } from '@/types/schema';
+
+/**
+ * The Accounts list only shows Email/Full Name/Created At, hiding role and
+ * storage usage that otherwise require opening each account individually.
+ * `createdAt` is dropped to make room; `roles` is a real property so it
+ * renders through the normal field pipeline, but `quotaUsage` is synthetic
+ * (not a real server property) — DynamicList resolves it to the
+ * `usedDiskQuota` + `quotas.maxDiskQuota` pair and formats it specially.
+ */
+export function withAccountListColumns(schema: Schema): Schema {
+  const list = schema.lists['x:Account/User'];
+  if (!list) return schema;
+
+  const columns = [
+    ...list.columns.filter((c) => c.name !== 'createdAt'),
+    { name: 'roles', label: 'Role' },
+    { name: 'quotaUsage', label: 'Usage / Quota' },
+  ];
+
+  return {
+    ...schema,
+    lists: {
+      ...schema.lists,
+      'x:Account/User': { ...list, columns },
+    },
+  };
+}