build: implement bundling system with Rollup

Phase 1-3 Complete:
- ✅ Installed Rollup with all required plugins
- ✅ Created rollup.config.js for UMD, ESM, CJS builds
- ✅ Created src/index.js entry point
- ✅ Created src/styles.css for CSS bundling
- ✅ Added ES6 exports to debug-system.js
- ✅ Excluded Node.js-only html-generator.js from bundle

Build outputs:
- dist/testdrive-jsui.js (217KB UMD)
- dist/testdrive-jsui.min.js (107KB minified!)
- dist/testdrive-jsui.esm.js (199KB ES Module)
- dist/testdrive-jsui.cjs.js (199KB CommonJS)
- dist/testdrive-jsui.css (minified, all styles inlined)

All builds include source maps for debugging.

package.json

@@ -37,12 +37,22 @@
   "devDependencies": {
     "@babel/core": "^7.23.0",
     "@babel/preset-env": "^7.23.0",
+    "@rollup/plugin-babel": "^6.1.0",
+    "@rollup/plugin-commonjs": "^29.0.0",
+    "@rollup/plugin-node-resolve": "^16.0.3",
+    "@rollup/plugin-terser": "^0.4.4",
+    "autoprefixer": "^10.4.23",
     "babel-jest": "^29.7.0",
+    "cssnano": "^7.1.2",
     "eslint": "^8.57.0",
     "eslint-config-standard": "^17.1.0",
     "eslint-plugin-jest": "^27.6.0",
     "jest": "^29.7.0",
-    "jest-environment-jsdom": "^29.7.0"
+    "jest-environment-jsdom": "^29.7.0",
+    "postcss": "^8.5.6",
+    "postcss-import": "^16.1.1",
+    "rollup": "^4.53.5",
+    "rollup-plugin-postcss": "^4.0.2"
   },
   "dependencies": {
     "jsdom": "^23.0.0"