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/app/globals.css

@@ -9,6 +9,12 @@
 @import "../themes/xp.css";
 @import "../themes/ninex.css";
 @import "../themes/ps2.css";
+@import "../themes/ps1.css";
+@import "../themes/ps3.css";
+@import "../themes/wii.css";
+@import "../themes/nds.css";
+@import "../themes/dreamcast.css";
+@import "../themes/jv2002.css";
 
 *,
 *::before,