Add atom-theme visual design (header/footer, theme system, restyled pages)

Faithful port of AtomCMS's "atom" theme look (light, Habbo-retro, golden
#eeb425 / amber #f59e0b accents, white cards, 12px radii, Nunito-first stack):
- globals.css: full token set + components (.site-header/.nav-item, .btn-*,
  .card, .hero, currency pills, article cards, inputs, tables, footer).
- SiteHeader (brand + nav + currency pills + auth box, staff-aware) + SiteFooter;
  layout wraps header/content/footer. Removed the bare SiteNav.
- Restyled home (hero + article cards), login (centered card).
- siteSettings now falls back to DEFAULTS on missing key OR DB error, so pages
  render without a DB; DATABASE_CONNECT_TIMEOUT_MS env + pool acquireTimeout make
  the no-DB fallback fast.

Verified in a real browser (computed styles): header white/sticky, golden logo
gradient, uppercase nav, amber primary button @12px radius, golden outline,
hero gradient — all correct. tsc exit 0, vitest 48/48, next build exit 0.

src/env.ts

@@ -8,6 +8,7 @@ const schema = z.object({
   DATABASE_URL: z.string().url(),
   DATABASE_POOL_SIZE: z.coerce.number().int().positive().default(40),
   DATABASE_IDLE_TIMEOUT_MS: z.coerce.number().int().positive().default(300_000),
+  DATABASE_CONNECT_TIMEOUT_MS: z.coerce.number().int().positive().default(10_000),
   HOTEL_NAME: z.string().default("Atom"),
   // RCON link to the Arcturus emulator (raw-JSON TCP protocol).
   RCON_HOST: z.string().default("127.0.0.1"),