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/lru_map/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "lru_map",
+  "version": "0.3.3",
+  "description": "Finite key-value map using the Least Recently Used (LRU) algorithm where the most recently used objects are keept in the map while less recently used items are evicted to make room for new ones.",
+  "main": "lru.js",
+  "typings": "lru.d.ts",
+  "scripts": {
+    "test": "node test.js && echo 'Verifying TypeScript definition...' && tsc --noEmit",
+    "prepublish": "npm test",
+    "benchmark": "node --expose-gc benchmark.js"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/rsms/js-lru.git"
+  },
+  "keywords": [
+    "cache",
+    "lru",
+    "buffer",
+    "map"
+  ],
+  "author": "Rasmus Andersson <me@rsms.me>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/rsms/js-lru/issues"
+  },
+  "homepage": "https://github.com/rsms/js-lru#readme",
+  "devDependencies": {
+    "typescript": "^2.0.10"
+  }
+}