feat(arena): add deterministic headless RL environments

package.json

@@ -5,12 +5,18 @@
   "license": "Apache-2.0",
   "type": "module",
   "main": "src/index.ts",
+  "exports": {
+    ".": "./src/index.ts",
+    "./arena": "./src/arena/index.ts",
+    "./*": "./src/*"
+  },
   "workspaces": [
     "server"
   ],
   "scripts": {
     "dev": "vite",
     "build": "tsc --noEmit && vite build",
+    "arena:source-hashes": "node scripts/check-arena-source-hashes.mjs",
     "provenance": "node scripts/check-provenance.mjs && node scripts/check-no-binaries.mjs",
     "licenses": "node scripts/check-dependency-licenses.mjs",
     "sbom": "npm sbom --package-lock-only --sbom-format=spdx",