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/tsconfig.json

@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "useDefineForClassFields": true,
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "isolatedModules": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "noFallthroughCasesInSwitch": true,
+    "forceConsistentCasingInFileNames": true,
+    "resolveJsonModule": true,
+    "paths": {
+      "@/*": ["./src/*"]
+    },
+    "baseUrl": "."
+  },
+  "include": ["src"]
+}