feat: add Mermaid to Excalidraw converter utility in frontend

frontend/src/utils/mermaidConverter.ts

@@ -0,0 +1,47 @@
+import { parseMermaidToExcalidraw, MermaidConfig } from '@excalidraw/mermaid-to-excalidraw';
+
+export interface MermaidConversionResult {
+  elements: any[];
+  files?: any;
+  error?: string;
+}
+
+/**
+ * Converts a Mermaid diagram definition to Excalidraw elements
+ * This function needs to run in the browser context as it requires DOM access
+ */
+export const convertMermaidToExcalidraw = async (
+  mermaidDefinition: string,
+  config?: MermaidConfig
+): Promise<MermaidConversionResult> => {
+  try {
+    // Parse the Mermaid diagram to Excalidraw elements
+    const result = await parseMermaidToExcalidraw(mermaidDefinition, config);
+    
+    return {
+      elements: result.elements,
+      files: result.files,
+    };
+  } catch (error) {
+    console.error('Error converting Mermaid to Excalidraw:', error);
+    return {
+      elements: [],
+      error: error instanceof Error ? error.message : String(error),
+    };
+  }
+};
+
+/**
+ * Default Mermaid configuration for Excalidraw conversion
+ */
+export const DEFAULT_MERMAID_CONFIG: MermaidConfig = {
+  startOnLoad: false,
+  flowchart: {
+    curve: 'linear',
+  },
+  themeVariables: {
+    fontSize: '20px',
+  },
+  maxEdges: 500,
+  maxTextSize: 50000,
+};