feat: add AccountsList with Add Account form; proxy POST /accounts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/app/accounts/page.tsx

@@ -1,4 +1,4 @@
-import { AccountCard } from './AccountCard';
+import { AccountsList } from './AccountsList';
 
 interface Account {
   id: string;
@@ -19,15 +19,7 @@ export default async function AccountsPage() {
   return (
     <div className="max-w-2xl">
       <h1 className="text-xl font-semibold mb-6">Accounts</h1>
-      {accounts.length === 0 ? (
-        <p className="text-gray-500">No accounts found.</p>
-      ) : (
-        <div className="flex flex-col gap-3">
-          {accounts.map((a) => (
-            <AccountCard key={a.id} account={a} />
-          ))}
-        </div>
-      )}
+      <AccountsList initialAccounts={accounts} />
     </div>
   );
 }