fix(excalidraw): pin React 18.3.1 exact version (esm.sh was resolving to React 19)

frontend/excalidraw-diag3.html

@@ -0,0 +1,86 @@
+<!DOCTYPE html>
+<html>
+<head><meta charset="UTF-8"><title>Excalidraw Error Capture</title>
+<style>
+  body { font-family:monospace; background:#1e1e1e; color:#ddd; padding:20px; }
+  .pass { color:#4caf50; } .fail { color:#f44336; }
+  pre { background:#2d2d2d; padding:10px; border-radius:4px; }
+  #app { margin-top:20px; border:1px dashed #555; min-height:100px; padding:10px; }
+</style>
+</head>
+<body>
+<h2>Excalidraw Error Boundary Test</h2>
+<pre id="log"></pre>
+<div id="app"></div>
+
+<script type="module">
+import React from "https://esm.sh/react@18";
+import ReactDOM from "https://esm.sh/react-dom@18/client";
+const log = document.getElementById('log');
+function add(msg, cls='') { log.innerHTML += `<span class="${cls}">${msg}</span>\n`; }
+
+// Error boundary to catch rendering errors
+class ErrorBoundary extends React.Component {
+  constructor(props) { super(props); this.state = { error: null }; }
+  static getDerivedStateFromError(error) { return { error }; }
+  componentDidCatch(error, info) {
+    add(`✗ REACT ERROR CAUGHT: ${error.message}`, 'fail');
+    add(`  Stack: ${(error.stack||'').split('\n').slice(0,5).join('\n')}`, 'info');
+  }
+  render() {
+    if (this.state.error) {
+      return React.createElement('div', { style: {color:'red',padding:'20px'} },
+        `Error: ${this.state.error.message}`
+      );
+    }
+    return this.props.children;
+  }
+}
+
+add('Loading Excalidraw...');
+try {
+  window.EXCALIDRAW_ASSET_PATH = 'https://esm.sh/@excalidraw/[email protected]/dist/prod/';
+  const ExcalidrawLib = await import('https://esm.sh/@excalidraw/[email protected]');
+  const { Excalidraw } = ExcalidrawLib;
+  
+  add(`Excalidraw keys: ${Object.keys(ExcalidrawLib).slice(0,8).join(', ')}`, 'info');
+  add(`Excalidraw itself: ${typeof Excalidraw}`, 'info');
+  if (typeof Excalidraw === 'function') {
+    add(`  .displayName: ${Excalidraw.displayName || 'none'}`, 'info');
+    add(`  .name: ${Excalidraw.name || 'none'}`, 'info');
+  }
+  
+  // Try rendering with error boundary
+  const root = ReactDOM.createRoot(document.getElementById('app'));
+  
+  try {
+    root.render(
+      React.createElement(ErrorBoundary, null,
+        React.createElement(Excalidraw, {
+          theme: 'dark',
+          excalidrawRef: (api) => {
+            add('✓ excalidrawRef CALLBACK FIRED!', 'pass');
+          },
+          onChange: () => {
+            add('  onChange called', 'info');
+          },
+          onPointerUpdate: () => {
+            // noisy, skip
+          }
+        })
+      )
+    );
+    add('render() executed - waiting...', 'info');
+  } catch(e) {
+    add(`✗ RENDER CRASH: ${e.message}`, 'fail');
+    add(`  ${e.stack}`, 'info');
+  }
+} catch(e) {
+  add(`✗ IMPORT ERROR: ${e.message}`, 'fail');
+  add(`  ${e.stack}`, 'info');
+}
+
+add('\nOpen browser console (F12) for more errors.', 'info');
+</script>
+</body>
+</html>