fix: prevent asset conflicts between React and Grid.js versions

Add coexistence checks to all enqueue methods to prevent loading
both React and Grid.js assets simultaneously.

Changes:
- ReactAdmin.php: Only enqueue React assets when ?react=1
- Init.php: Skip Grid.js when React active on admin pages
- Form.php, Coupon.php, Access.php: Restore classic assets when ?react=0
- Customer.php, Product.php, License.php: Add coexistence checks

Now the toggle between Classic and React versions works correctly.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

node_modules/lighthouse/report/generator/tsconfig.json

@@ -0,0 +1,16 @@
+{
+  "extends": "../../tsconfig-base.json",
+  "compilerOptions": {
+    // Limit defs to base JS and DOM (for URL: https://github.com/DefinitelyTyped/DefinitelyTyped/issues/34960).
+    "lib": ["es2020", "dom"],
+    // Only include `@types/node` from node_modules/.
+    "types": ["node"],
+  },
+  "references": [
+    {"path": "../../types/lhr/"},
+  ],
+  "include": [
+    "**/*.js",
+    "../../esm-utils.js",
+  ],
+}