feat(01-03): add /c/[token] Server Component route + layout

- src/app/c/[token]/page.tsx: Server Component calls getClientView(), notFound() on null
- src/app/c/[token]/layout.tsx: layout with metadata for client portal
- [Rule 1 - Bug] Renamed middleware.ts → proxy.ts and export middleware → proxy
  (Next.js 16 deprecated 'middleware' file convention; requires 'proxy' export name)
- params typed as Promise<{ token: string }> per Next.js 15+ breaking change
- npm run build: SUCCESS (no TypeScript errors)

src/app/c/[token]/layout.tsx

@@ -0,0 +1,14 @@
+import type { Metadata } from 'next';
+
+export const metadata: Metadata = {
+  title: 'Client Portal',
+  description: 'Project status dashboard',
+};
+
+export default function ClientLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return <>{children}</>;
+}

src/app/c/[token]/page.tsx

@@ -0,0 +1,28 @@
+import { getClientView } from '@/lib/client-view';
+import { notFound } from 'next/navigation';
+
+export const revalidate = 60; // ISR: revalidate every 60 seconds
+
+export default async function ClientDashboard({
+  params,
+}: {
+  params: Promise<{ token: string }>;
+}) {
+  const { token } = await params;
+  const view = await getClientView(token);
+
+  if (!view) {
+    notFound();
+  }
+
+  return (
+    <div className="min-h-screen bg-white">
+      {/* Placeholder: Dashboard UI will be built in Plan 04 */}
+      <div className="p-6">
+        <h1 className="text-2xl font-bold">{view.client.brand_name}</h1>
+        <p className="text-gray-600">{view.client.brief}</p>
+        <p className="text-sm text-gray-400 mt-2">Token: {token}</p>
+      </div>
+    </div>
+  );
+}