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/hooks/useContextMenu.ts

@@ -0,0 +1,27 @@
+import { useState, useCallback } from 'react';
+
+interface ContextMenuState {
+  visible: boolean;
+  x: number;
+  y: number;
+  nodeId: string | null;
+}
+
+export function useContextMenu() {
+  const [menuState, setMenuState] = useState<ContextMenuState>({
+    visible: false,
+    x: 0,
+    y: 0,
+    nodeId: null,
+  });
+
+  const show = useCallback((x: number, y: number, nodeId: string | null) => {
+    setMenuState({ visible: true, x, y, nodeId });
+  }, []);
+
+  const hide = useCallback(() => {
+    setMenuState((prev) => ({ ...prev, visible: false }));
+  }, []);
+
+  return { menuState, show, hide };
+}