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- Clean up outdated file references and duplicate assets

insertr-cli/pkg/content/assets/insertr.js

@@ -15,7 +15,7 @@ var Insertr = (function () {
         
         // Find all enhanced elements on the page
         findEnhancedElements() {
-            return document.querySelectorAll('[data-insertr-enhanced="true"]');
+            return document.querySelectorAll('.insertr');
         }
         
         // Get element metadata
@@ -608,7 +608,7 @@ var Insertr = (function () {
                 background-color: rgba(0, 124, 186, 0.05) !important;
             }
             
-            [data-insertr-enhanced="true"]:hover::after {
+            .insertr:hover::after {
                 content: "✏️ " attr(data-content-type);
                 position: absolute;
                 top: -25px;
@@ -1142,16 +1142,16 @@ var Insertr = (function () {
             }
 
             /* Hide editing interface when not in edit mode */
-            body:not(.insertr-edit-mode) [data-insertr-enhanced]:hover::after {
+            body:not(.insertr-edit-mode) .insertr:hover::after {
                 display: none !important;
             }
 
             /* Only show editing features when in edit mode */
-            .insertr-authenticated.insertr-edit-mode [data-insertr-enhanced] {
+            .insertr-authenticated.insertr-edit-mode .insertr {
                 cursor: pointer;
             }
 
-            .insertr-authenticated.insertr-edit-mode [data-insertr-enhanced]:hover {
+            .insertr-authenticated.insertr-edit-mode .insertr:hover {
                 outline: 2px dashed #007cba !important;
                 outline-offset: 2px !important;
                 background-color: rgba(0, 124, 186, 0.05) !important;
@@ -1203,25 +1203,25 @@ var Insertr = (function () {
         core: null,
         editor: null,
         auth: null,
-        
+
         // Initialize the library
         init(options = {}) {
             console.log('🔧 Insertr v1.0.0 initializing... (Hot Reload Ready)');
-            
+
             this.core = new InsertrCore(options);
             this.auth = new InsertrAuth(options);
             this.editor = new InsertrEditor(this.core, this.auth, options);
-            
+
             // Auto-initialize if DOM is ready
             if (document.readyState === 'loading') {
                 document.addEventListener('DOMContentLoaded', () => this.start());
             } else {
                 this.start();
             }
-            
+
             return this;
         },
-        
+
         // Start the system - only creates the minimal trigger
         start() {
             if (this.auth) {
@@ -1236,37 +1236,36 @@ var Insertr = (function () {
                 this.editor.start();
             }
         },
-        
+
         // Public API methods
         login() {
             return this.auth ? this.auth.toggleAuthentication() : null;
         },
-        
+
         logout() {
             if (this.auth && this.auth.isAuthenticated()) {
                 this.auth.toggleAuthentication();
             }
         },
-        
+
         toggleEditMode() {
             return this.auth ? this.auth.toggleEditMode() : null;
         },
-        
+
         isAuthenticated() {
             return this.auth ? this.auth.isAuthenticated() : false;
         },
-        
+
         isEditMode() {
             return this.auth ? this.auth.isEditMode() : false;
         },
-        
-        // Version info
-        version: '1.0.0'
+
+        // TODO: Version info based on package.json?
     };
 
     // Auto-initialize in development mode with proper DOM ready handling
     function autoInitialize() {
-        if (document.querySelector('[data-insertr-enhanced="true"]')) {
+        if (document.querySelector('.insertr')) {
             window.Insertr.init();
         }
     }

insertr-cli/pkg/content/injector.go

@@ -126,11 +126,11 @@ func (i *Injector) injectLinkContent(node *html.Node, content string) {
 	i.injectTextContent(node, content)
 }
 
-// addContentAttributes adds necessary data attributes for editor functionality
+// addContentAttributes adds necessary data attributes and insertr class for editor functionality
 func (i *Injector) addContentAttributes(node *html.Node, contentID string, contentType string) {
 	i.setAttribute(node, "data-content-id", contentID)
 	i.setAttribute(node, "data-content-type", contentType)
-	i.setAttribute(node, "data-insertr-enhanced", "true")
+	i.addClass(node, "insertr")
 }
 
 // InjectEditorAssets adds editor JavaScript and CSS to HTML document
@@ -193,6 +193,48 @@ func (i *Injector) setAttribute(node *html.Node, key, value string) {
 	})
 }
 
+// addClass safely adds a class to an HTML node
+func (i *Injector) addClass(node *html.Node, className string) {
+	var classAttr *html.Attribute
+	var classIndex int = -1
+
+	// Find existing class attribute
+	for idx, attr := range node.Attr {
+		if attr.Key == "class" {
+			classAttr = &attr
+			classIndex = idx
+			break
+		}
+	}
+
+	var classes []string
+	if classAttr != nil {
+		classes = strings.Fields(classAttr.Val)
+	}
+
+	// Check if class already exists
+	for _, class := range classes {
+		if class == className {
+			return // Class already exists
+		}
+	}
+
+	// Add new class
+	classes = append(classes, className)
+	newClassValue := strings.Join(classes, " ")
+
+	if classIndex >= 0 {
+		// Update existing class attribute
+		node.Attr[classIndex].Val = newClassValue
+	} else {
+		// Add new class attribute
+		node.Attr = append(node.Attr, html.Attribute{
+			Key: "class",
+			Val: newClassValue,
+		})
+	}
+}
+
 // Element represents a parsed HTML element with metadata
 type Element struct {
 	Node    *html.Node