feat: node creation and serialization logic in workflow editor

src/js/logic/pdf-workflow-page.ts

@@ -2,7 +2,11 @@ import { showAlert } from '../ui.js';
 import { tesseractLanguages } from '../config/tesseract-languages.js';
 import { createWorkflowEditor, updateNodeDisplay } from '../workflow/editor';
 import { executeWorkflow } from '../workflow/engine';
-import { nodeRegistry, getNodesByCategory } from '../workflow/nodes/registry';
+import {
+  nodeRegistry,
+  getNodesByCategory,
+  createNodeByType,
+} from '../workflow/nodes/registry';
 import type { BaseWorkflowNode } from '../workflow/nodes/base-node';
 import type { WorkflowEditor } from '../workflow/editor';
 import {
@@ -43,6 +47,7 @@ import {
 
 let workflowEditor: WorkflowEditor | null = null;
 let selectedNodeId: string | null = null;
+let deleteNodeHandler: EventListener | null = null;
 
 if (document.readyState === 'loading') {
   document.addEventListener('DOMContentLoaded', initializePage);
@@ -245,10 +250,14 @@ async function initializePage() {
     }
   });
 
-  document.addEventListener('wf-delete-node', ((e: CustomEvent) => {
+  if (deleteNodeHandler) {
+    document.removeEventListener('wf-delete-node', deleteNodeHandler);
+  }
+  deleteNodeHandler = ((e: CustomEvent) => {
     const nodeId = e.detail?.nodeId;
     if (nodeId) deleteNodeById(nodeId);
-  }) as EventListener);
+  }) as EventListener;
+  document.addEventListener('wf-delete-node', deleteNodeHandler);
 }
 
 async function deleteNodeById(nodeId: string) {
@@ -539,14 +548,12 @@ async function addNodeToCanvas(
   if (!workflowEditor) return;
   const { editor, area } = workflowEditor;
 
-  const entry = nodeRegistry[type];
-  if (!entry) {
-    console.error('Node type not found in registry:', type);
-    return;
-  }
-
   try {
-    const node = entry.factory();
+    const node = createNodeByType(type);
+    if (!node) {
+      console.error('Node type not found in registry:', type);
+      return;
+    }
     await editor.addNode(node);
 
     const pos = position || getCanvasCenter(area);