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/text-table/example/align.js

@@ -0,0 +1,8 @@
+var table = require('../');
+var t = table([
+    [ 'beep', '1024' ],
+    [ 'boop', '33450' ],
+    [ 'foo', '1006' ],
+    [ 'bar', '45' ]
+], { align: [ 'l', 'r' ] });
+console.log(t);

node_modules/text-table/example/center.js

@@ -0,0 +1,8 @@
+var table = require('../');
+var t = table([
+    [ 'beep', '1024', 'xyz' ],
+    [ 'boop', '3388450', 'tuv' ],
+    [ 'foo', '10106', 'qrstuv' ],
+    [ 'bar', '45', 'lmno' ]
+], { align: [ 'l', 'c', 'l' ] });
+console.log(t);

node_modules/text-table/example/dotalign.js

@@ -0,0 +1,9 @@
+var table = require('../');
+var t = table([
+    [ 'beep', '1024' ],
+    [ 'boop', '334.212' ],
+    [ 'foo', '1006' ],
+    [ 'bar', '45.6' ],
+    [ 'baz', '123.' ]
+], { align: [ 'l', '.' ] });
+console.log(t);

node_modules/text-table/example/doubledot.js

@@ -0,0 +1,11 @@
+var table = require('../');
+var t = table([
+    [ '0.1.2' ],
+    [ '11.22.33' ],
+    [ '5.6.7' ],
+    [ '1.22222' ],
+    [ '12345.' ],
+    [ '5555.' ],
+    [ '123' ]
+], { align: [ '.' ] });
+console.log(t);

node_modules/text-table/example/table.js

@@ -0,0 +1,6 @@
+var table = require('../');
+var t = table([
+    [ 'master', '0123456789abcdef' ],
+    [ 'staging', 'fedcba9876543210' ]
+]);
+console.log(t);