- package.json adds phaser, jspsych, and three plugins as deps;
  vite ^6.2 as devDep
- vite.config.js with base: './' so the bundle works under any
  sub-path (the library iframes it at /static/tasks/tiktik-web/)
- game/main.js and game/GameScene.js now use ES module imports
  instead of relying on globals injected by <script> tags
- levels/ and assets/ moved into public/ so Vite copies them
  verbatim into dist/; relative paths in code keep working
- index.html: all CDN tags removed; only the entry module remains
- .gitignore: add node_modules/ and dist/

Build output is ~11 MB total (1.6 MB JS, 374 KB gzipped) vs 55 MB
for the legacy Unity WebGL build. Library symlink should be
repointed at tasks/tiktik-web/dist/.