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/gradient-parser/bower.json

@@ -0,0 +1,31 @@
+{
+  "name": "gradient-parser",
+  "version": "0.1.5",
+  "main": "build/web.js",
+  "ignore": [
+    ".editorconfig",
+    ".gitattributes",
+    ".gitignore",
+    ".jshintrc",
+    ".npmignore",
+    ".travis.yml",
+    ".umd",
+    "gulpfile.js",
+    "npm-shrinkwrap.json",
+    "package.json",
+    "index.html",
+    "Makefile",
+    "build/node.js",
+    "README.md",
+    "gruntfile.js",
+    "lib/*",
+    "spec/*",
+    "LICENSE"
+  ],
+  "dependencies": {
+
+  },
+  "devDependencies": {
+
+  }
+}