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/globals.css

@@ -0,0 +1,81 @@
+:root {
+  --bg: #0f1217;
+  --panel: #171b22;
+  --border: #262c36;
+  --text: #e6e9ef;
+  --muted: #97a0ae;
+  --primary: #4f8cff;
+}
+
+* {
+  box-sizing: border-box;
+}
+
+body {
+  margin: 0;
+  background: var(--bg);
+  color: var(--text);
+  font-family: system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
+  line-height: 1.5;
+}
+
+a {
+  color: var(--primary);
+  text-decoration: none;
+}
+a:hover {
+  text-decoration: underline;
+}
+
+.container {
+  max-width: 960px;
+  margin: 0 auto;
+  padding: 1.5rem;
+}
+
+.site-nav {
+  border-bottom: 1px solid var(--border);
+  background: var(--panel);
+}
+.site-nav .container {
+  display: flex;
+  align-items: center;
+  gap: 1.25rem;
+  padding-top: 0.9rem;
+  padding-bottom: 0.9rem;
+}
+.site-nav .brand {
+  font-weight: 700;
+  color: var(--text);
+  font-size: 1.1rem;
+}
+.site-nav .spacer {
+  flex: 1;
+}
+
+.card {
+  background: var(--panel);
+  border: 1px solid var(--border);
+  border-radius: 10px;
+  padding: 1rem 1.2rem;
+}
+
+.grid {
+  display: grid;
+  gap: 1rem;
+}
+.grid.cols-2 {
+  grid-template-columns: repeat(2, 1fr);
+}
+
+.article-img {
+  width: 100%;
+  height: 140px;
+  object-fit: cover;
+  border-radius: 8px 8px 0 0;
+}
+
+.muted {
+  color: var(--muted);
+  font-size: 0.85rem;
+}