(feat): added mermaid rendering support in markdown (#676)

public/script/external/marked-mermaid.js

@@ -0,0 +1,70 @@
+// Marked.js extension for Mermaid diagrams
+function markedMermaid(options) {
+  options = options || {};
+  
+  return {
+    extensions: [
+      {
+        name: 'mermaid',
+        level: 'block',
+        start(src) {
+          return src.match(/^```mermaid/m)?.index;
+        },
+        tokenizer(src, tokens) {
+          const rule = /^```mermaid\n([\s\S]*?)\n```/;
+          const match = rule.exec(src);
+          if (match) {
+            return {
+              type: 'mermaid',
+              raw: match[0],
+              text: match[1].trim()
+            };
+          }
+        },
+        renderer(token) {
+          const id = 'mermaid-' + Math.random().toString(36).substr(2, 9);
+          
+          // Initialize Mermaid if not already done
+          if (typeof mermaid !== 'undefined' && !window.mermaidInitialized) {
+            mermaid.initialize({ 
+              startOnLoad: false,
+              theme: 'default',
+              securityLevel: 'loose'
+            });
+            window.mermaidInitialized = true;
+          }
+          
+          // Create a div that will be processed by Mermaid
+          const div = `<div class="mermaid" id="${id}">${token.text}</div>`;
+          
+          // Schedule Mermaid rendering for after DOM insertion
+          setTimeout(() => {
+            if (typeof mermaid !== 'undefined') {
+              try {
+                const element = document.getElementById(id);
+                if (element && !element.getAttribute('data-processed')) {
+                  mermaid.init(undefined, element);
+                  element.setAttribute('data-processed', 'true');
+                }
+              } catch (error) {
+                console.error('Mermaid rendering error:', error);
+              }
+            }
+          }, 0);
+          
+          return div;
+        }
+      }
+    ]
+  };
+}
+
+// Make it available globally
+if (typeof window !== 'undefined') {
+  window.markedMermaid = markedMermaid;
+}
+
+// CommonJS/Node.js export
+if (typeof module !== 'undefined' && module.exports) {
+  module.exports = markedMermaid;
+} 

public/script/utils.js

@@ -182,5 +182,6 @@ function renderMD(md, baseUrlValue) {
       throwOnError: false,
     })
   );
+  marked.use(markedMermaid());
   return DOMPurify.sanitize(marked.parse(md, { renderer }));
 }