refactor: restore root-level development workflow with enhanced tooling

- Add root package.json with development scripts and dependencies
- Move scripts/ from lib back to root for intuitive developer experience
- Clean lib/package.json to contain only runtime dependencies
- Add comprehensive justfile with cross-platform command shortcuts
- Update README.md with new development workflow instructions
- Maintain lib as clean, publishable package while enabling root-level commands

justfile

@@ -0,0 +1,93 @@
+# Insertr Development Commands
+# Use `just <command>` to run any of these tasks
+
+# Default recipe - show available commands
+default:
+    @just --list
+
+# Install all dependencies (root + lib)
+install:
+    npm install
+    cd lib && npm install
+
+# Start development server with live reload
+dev:
+    npm run dev
+
+# Start development server for about page
+dev-about:
+    npm run dev:about
+
+# Check project status and validate setup
+check:
+    npm run dev:check
+
+# Show demo instructions
+demo:
+    npm run dev:demo
+
+# Build the entire project (library + CLI)
+build:
+    npm run build
+
+# Build only the JavaScript library
+build-lib:
+    npm run build:lib
+
+# Watch library files for changes (auto-rebuild)
+watch:
+    cd lib && npm run dev
+
+# Start Air hot-reload for Go CLI development
+air:
+    cd insertr-cli && air
+
+# Build Go CLI only
+build-cli:
+    cd insertr-cli && go build -o insertr
+
+# Run CLI help
+cli-help:
+    cd insertr-cli && go run main.go --help
+
+# Parse demo site with CLI
+parse:
+    cd insertr-cli && go run main.go parse ../demo-site/
+
+# Start CLI development server
+servedev:
+    cd insertr-cli && go run main.go servedev -i ../demo-site -p 3000
+
+# Clean all build artifacts
+clean:
+    rm -rf lib/dist
+    rm -rf insertr-cli/insertr
+    rm -rf node_modules
+    rm -rf lib/node_modules
+
+# Lint code (placeholder for now)
+lint:
+    npm run lint
+
+# Run tests (placeholder for now)
+test:
+    npm run test
+
+# Development workflow: install deps, build lib, start dev server
+dev-setup: install build-lib dev
+
+# Production workflow: install deps, build everything
+prod-build: install build
+
+# Show project status
+status:
+    @echo "🏗️  Insertr Project Status"
+    @echo "========================="
+    @echo "📁 Root files:"
+    @ls -la package.json justfile 2>/dev/null || echo "   Missing files"
+    @echo "\n📚 Library files:"
+    @ls -la lib/package.json lib/src lib/dist 2>/dev/null || echo "   Missing library components"
+    @echo "\n🔧 CLI files:"
+    @ls -la insertr-cli/main.go insertr-cli/insertr 2>/dev/null || echo "   Missing CLI components"
+    @echo "\n🌐 Demo site:"
+    @ls -la demo-site/index.html demo-site/about.html 2>/dev/null || echo "   Missing demo files"