data: add Pokémon Nova to catalog + bump fixture counts

Nova (PhionGames RPG Maker XP / Essentials PC fangame) synced from the
vault export. Catalog 398->399, PC 78->79; banner manifest + Playwright
count fixtures updated. Built and deployed to romhacks.ginnoir.com.

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

src/generated/banner-manifest.json

@@ -223,6 +223,7 @@
   "nebula-3": "/assets/banners/nebula-3.png",
   "new-generations": "/assets/banners/new-generations.png",
   "nightmare": "/assets/banners/nightmare.webp",
+  "nova": "/assets/banners/nova.img",
   "null": "/assets/banners/null.png",
   "obscura": "/assets/banners/obscura.webp",
   "obsidian-emerald": "/assets/banners/obsidian-emerald.jpg",