refactor(web): migrate frontend to Tailwind CSS and Vike SSR

- Replace Mantine UI components with Tailwind CSS v4
- Migrate from static HTML to Vike-based SSR framework
- Disable SSR for game page (Emscripten requires browser environment)
- Simplify Emscripten loading to avoid hydration conflicts
- Remove Tailwind download logic from web.build.ts
- Add package manager lockfiles for reproducible builds
- Update .gitignore for node_modules and build artifacts

web/pages/+Head.tsx

@@ -1,13 +1,9 @@
 // https://vike.dev/Head
 
-//# BATI.has("mantine")
-import { ColorSchemeScript } from "@mantine/core";
-
 export default function HeadDefault() {
   return (
     <>
       <link rel="icon" href="/favicon.ico" />
-      <ColorSchemeScript />
     </>
   );
 }