Add Craft.js site builder (v2) - complete rebuild from GrapesJS

Rebuilt the visual site builder from scratch using Craft.js, React 18,
and TypeScript. The new editor renders directly in the DOM (no iframe),
supports 40+ components, multi-page with shared header/footer, 16
templates, full-spectrum color/gradient controls, custom head code
injection, save/publish workflow, and auto-save.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

craft/src/App.tsx

@@ -0,0 +1,26 @@
+import React from 'react';
+import { Editor } from '@craftjs/core';
+import { EditorShell } from './editor/EditorShell';
+import { componentResolver } from './components/resolver';
+import { WhpConfig } from './types';
+import { EditorConfigProvider } from './state/EditorConfigContext';
+import { SiteDesignProvider } from './state/SiteDesignContext';
+import { PageProvider } from './state/PageContext';
+
+interface AppProps {
+  whpConfig: WhpConfig | null;
+}
+
+export const App: React.FC<AppProps> = ({ whpConfig }) => {
+  return (
+    <EditorConfigProvider config={whpConfig}>
+      <SiteDesignProvider>
+        <Editor resolver={componentResolver} enabled={true}>
+          <PageProvider>
+            <EditorShell />
+          </PageProvider>
+        </Editor>
+      </SiteDesignProvider>
+    </EditorConfigProvider>
+  );
+};