feat(scala): Scala.js browser platform, snake and pong pages, build-web.sh

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scala/build-web.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Usage: ./build-web.sh
+# Compiles src/ + web/ to JavaScript with Scala.js: web/dist/snake.js (index.html) and web/dist/pong.js (pong.html).
+# Then serve the repo root (node scripts/serve.mjs) and open http://localhost:8000/scala/index.html.
+set -euo pipefail
+cd "$(dirname "$0")"
+SCALA_CLI="${SCALA_CLI:-$(command -v scala-cli || echo "$HOME/.local/bin/scala-cli")}"
+mkdir -p web/dist
+build() { # <main class> <output file>
+  "$SCALA_CLI" --power package --js --js-module-kind es src web project.scala --main-class "$1" -o "$2" -f
+}
+build snake.web.SnakeMain web/dist/snake.js
+build snake.web.PongMain web/dist/pong.js