build: configure npm package for publication

Phase 4-5 Complete:
- ✅ Updated package.json to v1.0.0 with proper entry points
- ✅ Added peer dependency on marked.js (^11.0.0 || ^12.0.0 || ^13.0.0)
- ✅ Set module type to ESM to fix Rollup warnings
- ✅ Configured files array for distribution (dist/ only)
- ✅ Added prepublishOnly script (build + test)
- ✅ Created .npmignore to exclude dev files
- ✅ Created CHANGELOG.md following Keep a Changelog format

Package details:
- Main: dist/testdrive-jsui.cjs.js (CommonJS)
- Module: dist/testdrive-jsui.esm.js (ES Module)
- Browser: dist/testdrive-jsui.min.js (107KB minified)
- Style: dist/testdrive-jsui.css
- Total package size: 445.9 KB (13 files)

npm pack --dry-run verified successfully!

package.json

@@ -1,39 +1,68 @@
 {
   "name": "testdrive-jsui",
-  "version": "0.1.0",
-  "description": "JavaScript UI testing framework capability for MarkiTect",
-  "main": "js/index.js",
-  "directories": {
-    "test": "js/tests"
-  },
+  "version": "1.0.0",
+  "description": "JavaScript-first markdown editor library with interactive UI",
+  "type": "module",
+  "main": "dist/testdrive-jsui.cjs.js",
+  "module": "dist/testdrive-jsui.esm.js",
+  "browser": "dist/testdrive-jsui.min.js",
+  "style": "dist/testdrive-jsui.css",
+  "unpkg": "dist/testdrive-jsui.min.js",
+  "jsdelivr": "dist/testdrive-jsui.min.js",
+  "types": "dist/index.d.ts",
+  "files": [
+    "dist/",
+    "README.md",
+    "LICENSE",
+    "CHANGELOG.md"
+  ],
   "scripts": {
+    "build": "rollup -c",
+    "build:watch": "rollup -c -w",
+    "build:prod": "NODE_ENV=production rollup -c",
+    "dev": "npm run build:watch",
     "test": "jest",
     "test:watch": "jest --watch",
     "test:coverage": "jest --coverage",
     "test:verbose": "jest --verbose",
-    "test:specific": "jest --testNamePattern",
-    "lint": "eslint js/**/*.js",
-    "lint:fix": "eslint js/**/*.js --fix",
-    "dev": "npm run test:watch",
-    "build": "echo 'No build step required for this package'",
-    "clean": "rm -rf coverage/ .nyc_output/ node_modules/.cache/"
+    "prepublishOnly": "npm run build:prod && npm test",
+    "lint": "eslint js/**/*.js src/**/*.js",
+    "lint:fix": "eslint js/**/*.js src/**/*.js --fix",
+    "clean": "rm -rf dist/ coverage/ .nyc_output/ node_modules/.cache/",
+    "size": "npm run build:prod && du -h dist/*"
   },
   "repository": {
     "type": "git",
     "url": "https://github.com/markitect/testdrive-jsui.git"
   },
   "keywords": [
+    "markdown",
+    "editor",
     "javascript",
-    "testing",
     "ui",
-    "framework",
-    "markitect",
-    "tdd",
-    "dom",
-    "components"
+    "wysiwyg",
+    "contenteditable",
+    "section-editing",
+    "interactive",
+    "browser",
+    "frontend",
+    "marked",
+    "markdown-editor"
   ],
-  "author": "MarkiTect Project",
+  "author": "MarkiTect Team <team@markitect.dev>",
   "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/markitect/testdrive-jsui/issues"
+  },
+  "homepage": "https://github.com/markitect/testdrive-jsui#readme",
+  "peerDependencies": {
+    "marked": "^11.0.0 || ^12.0.0 || ^13.0.0"
+  },
+  "peerDependenciesMeta": {
+    "marked": {
+      "optional": false
+    }
+  },
   "devDependencies": {
     "@babel/core": "^7.23.0",
     "@babel/preset-env": "^7.23.0",
@@ -57,6 +86,10 @@
   "dependencies": {
     "jsdom": "^23.0.0"
   },
+  "engines": {
+    "node": ">=14.0.0",
+    "npm": ">=6.0.0"
+  },
   "jest": {
     "testEnvironment": "jsdom",
     "testMatch": [