refactor: consolidate all Node.js development into lib package

- Move scripts/ to lib/scripts/ and convert to ESM modules
- Consolidate dependencies: add live-server to lib/package.json
- Remove root package.json and node_modules split
- Preserve CLI integration via existing rebuild-library.sh
- Add development quickstart guide for new unified workflow
- Clean up outdated file references and duplicate assets

lib/scripts/dev.js

@@ -0,0 +1,115 @@
+#!/usr/bin/env node
+
+/**
+ * Development helper script for Insertr
+ * Provides common development tasks and utilities
+ */
+
+import { execSync, spawn } from 'child_process';
+import fs from 'fs';
+import path from 'path';
+
+const commands = {
+  serve: {
+    description: 'Start development server with live reload',
+    action: () => {
+      console.log('🚀 Starting Insertr development server...');
+      console.log('📂 Serving demo-site/ at http://localhost:3000');
+      console.log('🔄 Live reload enabled');
+      console.log('\n💡 Test the three user types:');
+      console.log('   👥 Customer: Visit the site normally');
+      console.log('   ✏️  Client: Click "Login as Client" → "Edit Mode: On"');
+      console.log('   🔧 Developer: View source to see integration\n');
+      
+       spawn('npx', ['live-server', '../demo-site', '--port=3000', '--open=/index.html'], {
+        stdio: 'inherit'
+      });
+    }
+  },
+
+  check: {
+    description: 'Check project status and validate setup',
+    action: () => {
+      console.log('🔍 Checking Insertr project status...\n');
+      
+      // Check files exist
+       const requiredFiles = [
+         '../demo-site/index.html',
+         '../demo-site/about.html', 
+         'dist/insertr.js',
+         'dist/insertr.min.js',
+         'package.json'
+       ];
+      
+      let allGood = true;
+      
+      requiredFiles.forEach(file => {
+        if (fs.existsSync(file)) {
+          console.log('✅', file);
+        } else {
+          console.log('❌', file, '(missing)');
+          allGood = false;
+        }
+      });
+      
+      if (allGood) {
+        console.log('\n🎉 All core files present!');
+        console.log('\n📊 Project stats:');
+        
+         // Count editable elements
+         const indexContent = fs.readFileSync('../demo-site/index.html', 'utf8');
+         const aboutContent = fs.readFileSync('../demo-site/about.html', 'utf8');
+         const insertrMatches = (indexContent + aboutContent).match(/class="insertr"/g) || [];
+         console.log(`   📝 Editable elements: ${insertrMatches.length}`);
+         
+         // Check library size
+         const libSize = fs.statSync('dist/insertr.js').size;
+         console.log(`   📦 Library size: ${(libSize / 1024).toFixed(1)}KB`);
+        
+         console.log('\n🚀 Ready to develop! Run: npm run serve');
+      } else {
+        console.log('\n❌ Some files are missing. Please check your setup.');
+        process.exit(1);
+      }
+    }
+  },
+
+  demo: {
+    description: 'Show demo instructions',
+    action: () => {
+      console.log('🎬 Insertr Demo Instructions\n');
+       console.log('1. 🌐 Start server: npm run serve');
+      console.log('2. 👀 Customer view: Browse the site normally');
+      console.log('3. 🔑 Client login: Click "Login as Client"');
+      console.log('4. ✏️  Edit mode: Click "Edit Mode: Off" to enable editing');
+      console.log('5. 📝 Edit content: Click any ✏️ button to edit');
+      console.log('6. 🔄 Try different content types (simple text vs rich markdown)');
+      console.log('7. 📄 Multi-page: Navigate to About page to see persistence\n');
+      console.log('🎯 Key features to test:');
+      console.log('   • Inline text editing');
+      console.log('   • Markdown editing for rich content');
+      console.log('   • Auto-save with visual feedback');
+      console.log('   • Content persistence across pages');
+      console.log('   • Responsive design on mobile\n');
+    }
+  }
+};
+
+// Parse command line arguments
+const command = process.argv[2] || 'help';
+
+if (commands[command]) {
+  commands[command].action();
+} else if (command === 'help' || command === '--help' || command === '-h') {
+  console.log('🛠️  Insertr Development Helper\n');
+  console.log('Available commands:\n');
+  Object.entries(commands).forEach(([name, cmd]) => {
+    console.log(`  ${name.padEnd(12)} ${cmd.description}`);
+  });
+  console.log('\nUsage: node scripts/dev.js <command>');
+  console.log('   or: npm run check\n');
+} else {
+  console.log(`❌ Unknown command: ${command}`);
+  console.log('Run: node scripts/dev.js help');
+  process.exit(1);
+}