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/pure-rand/lib/distribution/UniformArrayIntDistribution.js

@@ -0,0 +1,15 @@
+"use strict";
+exports.__esModule = true;
+exports.uniformArrayIntDistribution = void 0;
+var UnsafeUniformArrayIntDistribution_1 = require("./UnsafeUniformArrayIntDistribution");
+function uniformArrayIntDistribution(from, to, rng) {
+    if (rng != null) {
+        var nextRng = rng.clone();
+        return [(0, UnsafeUniformArrayIntDistribution_1.unsafeUniformArrayIntDistribution)(from, to, nextRng), nextRng];
+    }
+    return function (rng) {
+        var nextRng = rng.clone();
+        return [(0, UnsafeUniformArrayIntDistribution_1.unsafeUniformArrayIntDistribution)(from, to, nextRng), nextRng];
+    };
+}
+exports.uniformArrayIntDistribution = uniformArrayIntDistribution;