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/@emotion/hash/src/index.ts

@@ -0,0 +1,63 @@
+/* eslint-disable */
+// Inspired by https://github.com/garycourt/murmurhash-js
+// Ported from https://github.com/aappleby/smhasher/blob/61a0530f28277f2e850bfc39600ce61d02b518de/src/MurmurHash2.cpp#L37-L86
+
+export default function murmur2(str: string): string {
+  // 'm' and 'r' are mixing constants generated offline.
+  // They're not really 'magic', they just happen to work well.
+
+  // const m = 0x5bd1e995;
+  // const r = 24;
+
+  // Initialize the hash
+
+  var h = 0
+
+  // Mix 4 bytes at a time into the hash
+
+  var k,
+    i = 0,
+    len = str.length
+  for (; len >= 4; ++i, len -= 4) {
+    k =
+      (str.charCodeAt(i) & 0xff) |
+      ((str.charCodeAt(++i) & 0xff) << 8) |
+      ((str.charCodeAt(++i) & 0xff) << 16) |
+      ((str.charCodeAt(++i) & 0xff) << 24)
+
+    k =
+      /* Math.imul(k, m): */
+      (k & 0xffff) * 0x5bd1e995 + (((k >>> 16) * 0xe995) << 16)
+    k ^= /* k >>> r: */ k >>> 24
+
+    h =
+      /* Math.imul(k, m): */
+      ((k & 0xffff) * 0x5bd1e995 + (((k >>> 16) * 0xe995) << 16)) ^
+      /* Math.imul(h, m): */
+      ((h & 0xffff) * 0x5bd1e995 + (((h >>> 16) * 0xe995) << 16))
+  }
+
+  // Handle the last few bytes of the input array
+
+  switch (len) {
+    case 3:
+      h ^= (str.charCodeAt(i + 2) & 0xff) << 16
+    case 2:
+      h ^= (str.charCodeAt(i + 1) & 0xff) << 8
+    case 1:
+      h ^= str.charCodeAt(i) & 0xff
+      h =
+        /* Math.imul(h, m): */
+        (h & 0xffff) * 0x5bd1e995 + (((h >>> 16) * 0xe995) << 16)
+  }
+
+  // Do a few final mixes of the hash to ensure the last few
+  // bytes are well-incorporated.
+
+  h ^= h >>> 13
+  h =
+    /* Math.imul(h, m): */
+    (h & 0xffff) * 0x5bd1e995 + (((h >>> 16) * 0xe995) << 16)
+
+  return ((h ^ (h >>> 15)) >>> 0).toString(36)
+}