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/picomatch/package.json

@@ -0,0 +1,81 @@
+{
+  "name": "picomatch",
+  "description": "Blazing fast and accurate glob matcher written in JavaScript, with no dependencies and full support for standard and extended Bash glob features, including braces, extglobs, POSIX brackets, and regular expressions.",
+  "version": "2.3.2",
+  "homepage": "https://github.com/micromatch/picomatch",
+  "author": "Jon Schlinkert (https://github.com/jonschlinkert)",
+  "funding": "https://github.com/sponsors/jonschlinkert",
+  "repository": "micromatch/picomatch",
+  "bugs": {
+    "url": "https://github.com/micromatch/picomatch/issues"
+  },
+  "license": "MIT",
+  "files": [
+    "index.js",
+    "lib"
+  ],
+  "main": "index.js",
+  "engines": {
+    "node": ">=8.6"
+  },
+  "scripts": {
+    "lint": "eslint --cache --cache-location node_modules/.cache/.eslintcache --report-unused-disable-directives --ignore-path .gitignore .",
+    "mocha": "mocha --reporter dot",
+    "test": "npm run lint && npm run mocha",
+    "test:ci": "npm run test:cover",
+    "test:cover": "nyc npm run mocha"
+  },
+  "devDependencies": {
+    "eslint": "^6.8.0",
+    "fill-range": "^7.0.1",
+    "gulp-format-md": "^2.0.0",
+    "mocha": "^6.2.2",
+    "nyc": "^15.0.0",
+    "time-require": "github:jonschlinkert/time-require"
+  },
+  "keywords": [
+    "glob",
+    "match",
+    "picomatch"
+  ],
+  "nyc": {
+    "reporter": [
+      "html",
+      "lcov",
+      "text-summary"
+    ]
+  },
+  "verb": {
+    "toc": {
+      "render": true,
+      "method": "preWrite",
+      "maxdepth": 3
+    },
+    "layout": "empty",
+    "tasks": [
+      "readme"
+    ],
+    "plugins": [
+      "gulp-format-md"
+    ],
+    "lint": {
+      "reflinks": true
+    },
+    "related": {
+      "list": [
+        "braces",
+        "micromatch"
+      ]
+    },
+    "reflinks": [
+      "braces",
+      "expand-brackets",
+      "extglob",
+      "fill-range",
+      "micromatch",
+      "minimatch",
+      "nanomatch",
+      "picomatch"
+    ]
+  }
+}