Add data-driven public pages (home, news, profile)

Real App Router pages reading the converted Prisma models:
- home: latest 4 articles (websiteArticles) + hotel_name from settings
- /news + /news/[slug]: article index and detail
- /u/[username]: profile (avatar via imager helper, motto, rank, credits, online)
- shared SiteNav (reads session via auth() + hotel_name), globals.css
- src/lib/format.ts: avatarImageUrl + excerpt helpers (unit-tested)

Verified: tsc exit 0, vitest 43/43, next build exit 0 (7 routes). Pages render
against a live DB (deferred until DATABASE_URL is provided). i18n to be layered
on next.

src/app/news/[slug]/page.tsx

@@ -0,0 +1,35 @@
+import Link from "next/link";
+import { notFound } from "next/navigation";
+import { prisma } from "@/lib/prisma";
+
+export const dynamic = "force-dynamic";
+
+export default async function ArticlePage({
+  params,
+}: {
+  params: Promise<{ slug: string }>;
+}) {
+  const { slug } = await params;
+  const article = await prisma.websiteArticles.findUnique({ where: { slug } });
+  if (!article) notFound();
+
+  return (
+    <main>
+      <p className="muted">
+        <Link href="/news">← News</Link>
+      </p>
+      <h1>{article.title}</h1>
+      {article.createdAt ? (
+        <p className="muted">{article.createdAt.toISOString().slice(0, 10)}</p>
+      ) : null}
+      {article.image ? (
+        <img
+          src={article.image}
+          alt=""
+          style={{ width: "100%", borderRadius: 10, margin: "1rem 0" }}
+        />
+      ) : null}
+      <div style={{ whiteSpace: "pre-wrap" }}>{article.fullStory}</div>
+    </main>
+  );
+}