feat: add 6 more skins (PS1, PS3, Wii, NDS, Dreamcast, JV2002)

Brings the catalog to nine. Each is a single scoped [data-theme="..."]
CSS file plus a registry entry — no markup changes.

- ps1: charcoal BIOS, gray panels, uppercase letterspacing
- ps3: animated XMB sky gradient + drifting wave, black glass
- wii: white channels, rounded pills, soft blue glow
- nds: silver shell with content framed as the touch screen
- dreamcast: cream BIOS, conic-gradient orange swirl, lowercase blue
- jv2002: dense boxy portal, Verdana 11px, red masthead, blue nav tabs

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/Shell.tsx

@@ -1,12 +1,14 @@
 import Link from "next/link";
 import type { ReactNode } from "react";
-import { type ThemeId } from "@/themes/registry";
+import { THEMES, type ThemeId } from "@/themes/registry";
+import { getSettings } from "@/lib/settings";
+import { isAdmin } from "@/lib/auth";
 import ThemeSwitcher from "./ThemeSwitcher";
 import Clock from "./Clock";
 
 // Shared, theme-agnostic page chrome. Every theme restyles these `rb-` classes
 // to look like its own OS/console. The HTML skeleton never changes.
-export default function Shell({
+export default async function Shell({
   theme,
   title,
   children,
@@ -15,12 +17,24 @@ export default function Shell({
   title: string;
   children: ReactNode;
 }) {
+  const settings = getSettings();
+  const admin = await isAdmin();
+
+  // Admins always get the switcher with every skin; the public only sees it when
+  // enabled, and only the allowed skins.
+  const showSwitcher = admin || settings.publicThemeToggle;
+  const switcherThemes = admin
+    ? THEMES
+    : THEMES.filter((t) => settings.allowedThemes.includes(t.id));
+
   return (
     <div className="rb-desktop">
       <div className="rb-window" role="application">
         <div className="rb-titlebar">
           <span className="rb-titlebar-icon" aria-hidden />
-          <span className="rb-titlebar-text">{title} — RetroBlog</span>
+          <span className="rb-titlebar-text">
+            {title} — {settings.title}
+          </span>
           <div className="rb-titlebar-buttons" aria-hidden>
             <button className="rb-tb-btn rb-tb-min" tabIndex={-1}>
               <span>_</span>
@@ -41,16 +55,15 @@ export default function Shell({
           <Link className="rb-menu-link" href="/about">
             About
           </Link>
-          <a
-            className="rb-menu-link"
-            href="https://github.com"
-            target="_blank"
-            rel="noreferrer"
-          >
-            Links
-          </a>
+          {admin && (
+            <Link className="rb-menu-link" href="/admin">
+              Admin
+            </Link>
+          )}
           <span className="rb-spacer" />
-          <ThemeSwitcher initial={theme} />
+          {showSwitcher && (
+            <ThemeSwitcher initial={theme} themes={switcherThemes} />
+          )}
         </nav>
 
         <div className="rb-content">{children}</div>
@@ -58,7 +71,7 @@ export default function Shell({
         <div className="rb-statusbar">
           <span className="rb-status-cell">Ready</span>
           <span className="rb-status-cell rb-status-grow">
-            RetroBlog v0.1
+            {settings.footer}
           </span>
         </div>
       </div>
@@ -71,7 +84,7 @@ export default function Shell({
         <div className="rb-tasks">
           <button className="rb-task rb-task-active">
             <span className="rb-task-icon" aria-hidden />
-            RetroBlog
+            {settings.title}
           </button>
         </div>
         <div className="rb-tray">