feat: complete code cleanup and create feature parity plan

Major Architecture Improvements:
- Separate JavaScript library (lib/) with proper build system
- Go CLI with embedded library using go:embed
- Hot reload development with Air integration
- Library + CLI build pipeline with npm run build

Code Cleanup:
- Remove obsolete assets (insertr-cli/assets/editor/)
- Clean up package.json metadata and dependencies
- Update .gitignore for new architecture
- Remove unused 'marked' dependency

New Documentation:
- Add comprehensive TODO.md with feature gap analysis
- Document critical gaps between prototype and current library
- Create phased implementation plan for feature parity
- Update DEVELOPMENT.md with hot reload workflow
- Add LIBRARY.md documenting new architecture

Hot Reload System:
- Air watches both Go CLI and JavaScript library
- Library changes trigger: rebuild → copy → CLI rebuild → serve
- Seamless development experience across full stack

Next Steps:
- Current library is basic proof-of-concept (prompt() editing)
- Archived prototype has production-ready features
- Phase 1 focuses on professional forms and authentication
- Phase 2 adds validation and content persistence

insertr-cli/pkg/content/injector.go

@@ -133,7 +133,7 @@ func (i *Injector) addContentAttributes(node *html.Node, contentID string, conte
 }
 
 // InjectEditorAssets adds editor JavaScript and CSS to HTML document
-func (i *Injector) InjectEditorAssets(doc *html.Node, isDevelopment bool) {
+func (i *Injector) InjectEditorAssets(doc *html.Node, isDevelopment bool, libraryScript string) {
 	if !isDevelopment {
 		return // Only inject in development mode for now
 	}
@@ -144,15 +144,21 @@ func (i *Injector) InjectEditorAssets(doc *html.Node, isDevelopment bool) {
 		return
 	}
 
-	// Add editor JavaScript
+	// Add inline script with embedded library
 	script := &html.Node{
 		Type: html.ElementNode,
 		Data: "script",
 		Attr: []html.Attribute{
-			{Key: "src", Val: "/_insertr/insertr-editor.js"},
-			{Key: "defer", Val: ""},
+			{Key: "type", Val: "text/javascript"},
 		},
 	}
+
+	// Add the library content as text node
+	textNode := &html.Node{
+		Type: html.TextNode,
+		Data: libraryScript,
+	}
+	script.AppendChild(textNode)
 	head.AppendChild(script)
 }