feat(accounts): add Aliases count column to Accounts and Groups

Same pattern as the existing quotaUsage deviation: neither list's
schema exposes an alias count as a column, only the full `aliases`
objectList on the detail view. Added a synthetic `aliasCount` column
(SCHEMA-DEVIATION: account-alias-count-column, documented in
SCHEMA_DEVIATIONS.md) that DynamicList resolves by fetching the real
`aliases` property and counting its entries.

Verified against a live test server: adding a real alias to an
account correctly bumps its Aliases count from 0 to 1 in the list.

SCHEMA_DEVIATIONS.md

@@ -67,6 +67,13 @@ itself stays byte-for-byte alignable with upstream's version of the file.
 - **Why**: the `x:Application` list schema is not guaranteed to expose `enabled` as a list column, even though it's a real object property (fetched separately via `properties.push('enabled')`).
 - **Ideal fix**: the server's `x:Application` list schema always includes `enabled` as a real column; the fallback branch is deleted (only the reordering logic remains, which is not a deviation).
 
+### `account-alias-count-column` 🟡
+
+- **Where**: [`src/lib/accountColumns.ts`](src/lib/accountColumns.ts), rendering in [`src/components/lists/DynamicList.tsx`](src/components/lists/DynamicList.tsx)
+- **What**: adds a synthetic `aliasCount` column to the `x:Account/User` and `x:Account/Group` lists — not a real schema property; `DynamicList` resolves it from the real `aliases` objectList property and renders its entry count.
+- **Why**: neither list's schema exposes alias count as a column, only the full `aliases` list on the detail view.
+- **Ideal fix**: the server's `x:Account/User` and `x:Account/Group` list schemas include a computed alias-count column natively; this column definition is deleted.
+
 ## Not a deviation (for reference)
 
 A few other `viewName === '...'` / `objectName === '...'` checks exist in

src/components/lists/DynamicList.tsx

@@ -503,6 +503,8 @@ export function DynamicList({ viewName }: DynamicListProps) {
   // (see withAccountListColumns, account-quota-usage-column deviation)
   // include the synthetic `quotaUsage` column gets it resolved and rendered.
   const hasQuotaUsageColumn = (resolved?.list?.columns ?? []).some((c) => c.name === 'quotaUsage');
+  // SCHEMA-DEVIATION: account-alias-count-column (see SCHEMA_DEVIATIONS.md)
+  const hasAliasCountColumn = (resolved?.list?.columns ?? []).some((c) => c.name === 'aliasCount');
 
   const displayColumns = useMemo(() => {
     const columns = resolved?.list?.columns ?? [];
@@ -671,6 +673,12 @@ export function DynamicList({ viewName }: DynamicListProps) {
             properties.splice(quotaIdx, 1, 'usedDiskQuota', 'quotas');
           }
         }
+        if (hasAliasCountColumn) {
+          const aliasIdx = properties.indexOf('aliasCount');
+          if (aliasIdx !== -1) {
+            properties.splice(aliasIdx, 1, 'aliases');
+          }
+        }
         if (isMailboxList && !properties.includes('parentId')) {
           properties.push('parentId');
         }
@@ -755,7 +763,18 @@ export function DynamicList({ viewName }: DynamicListProps) {
         setLoading(false);
       }
     },
-    [resolved, schema, buildFilter, buildSort, isWebApplications, isAccountsList, hasQuotaUsageColumn, isMailboxList, activeClientFilters],
+    [
+      resolved,
+      schema,
+      buildFilter,
+      buildSort,
+      isWebApplications,
+      isAccountsList,
+      hasQuotaUsageColumn,
+      hasAliasCountColumn,
+      isMailboxList,
+      activeClientFilters,
+    ],
   );
 
   useEffect(() => {
@@ -1680,6 +1699,8 @@ export function DynamicList({ viewName }: DynamicListProps) {
                             formatUserRole(item, schema!)
                           ) : hasQuotaUsageColumn && col.name === 'quotaUsage' ? (
                             renderQuotaUsage(item, t)
+                          ) : hasAliasCountColumn && col.name === 'aliasCount' ? (
+                            Object.keys((item.aliases as Record<string, unknown>) ?? {}).length
                           ) : isMailboxList && col.name === 'name' ? (
                             (() => {
                               const depth = mailboxDepths.get(item.id as string) ?? 0;

src/lib/accountColumns.ts

@@ -19,6 +19,12 @@ import type { Schema } from '@/types/schema';
  * The Groups list gets the same `quotaUsage` column (groups have their own
  * `usedDiskQuota`/`quotas`, same as users), but not `roles` — that column
  * is specific to the Users list.
+ *
+ * SCHEMA-DEVIATION: account-alias-count-column (see SCHEMA_DEVIATIONS.md)
+ *
+ * Both lists also get a synthetic `aliasCount` column — DynamicList
+ * resolves it from the real `aliases` objectList property (an id-keyed
+ * map, per JMAP's objectList wire format) and renders its entry count.
  */
 export function withAccountListColumns(schema: Schema): Schema {
   let lists = schema.lists;
@@ -29,13 +35,18 @@ export function withAccountListColumns(schema: Schema): Schema {
       ...userList.columns.filter((c) => c.name !== 'createdAt'),
       { name: 'roles', label: 'Role' },
       { name: 'quotaUsage', label: 'Usage / Quota' },
+      { name: 'aliasCount', label: 'Aliases' },
     ];
     lists = { ...lists, 'x:Account/User': { ...userList, columns } };
   }
 
   const groupList = lists['x:Account/Group'];
   if (groupList) {
-    const columns = [...groupList.columns, { name: 'quotaUsage', label: 'Usage / Quota' }];
+    const columns = [
+      ...groupList.columns,
+      { name: 'quotaUsage', label: 'Usage / Quota' },
+      { name: 'aliasCount', label: 'Aliases' },
+    ];
     lists = { ...lists, 'x:Account/Group': { ...groupList, columns } };
   }