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/ajv/lib/dot/propertyNames.jst

@@ -0,0 +1,52 @@
+{{# def.definitions }}
+{{# def.errors }}
+{{# def.setupKeyword }}
+{{# def.setupNextLevel }}
+
+var {{=$errs}} = errors;
+
+{{? {{# def.nonEmptySchema:$schema }} }}
+  {{
+    $it.schema = $schema;
+    $it.schemaPath = $schemaPath;
+    $it.errSchemaPath = $errSchemaPath;
+  }}
+
+  {{
+    var $key = 'key' + $lvl
+      , $idx = 'idx' + $lvl
+      , $i = 'i' + $lvl
+      , $invalidName = '\' + ' + $key + ' + \''
+      , $dataNxt = $it.dataLevel = it.dataLevel + 1
+      , $nextData = 'data' + $dataNxt
+      , $dataProperties = 'dataProperties' + $lvl
+      , $ownProperties = it.opts.ownProperties
+      , $currentBaseId = it.baseId;
+  }}
+
+  {{? $ownProperties }}
+    var {{=$dataProperties}} = undefined;
+  {{?}}
+  {{# def.iterateProperties }}
+    var startErrs{{=$lvl}} = errors;
+
+    {{ var $passData = $key; }}
+    {{# def.setCompositeRule }}
+    {{# def.generateSubschemaCode }}
+    {{# def.optimizeValidate }}
+    {{# def.resetCompositeRule }}
+
+    if (!{{=$nextValid}}) {
+      for (var {{=$i}}=startErrs{{=$lvl}}; {{=$i}}<errors; {{=$i}}++) {
+        vErrors[{{=$i}}].propertyName = {{=$key}};
+      }
+      {{# def.extraError:'propertyNames' }}
+      {{? $breakOnError }} break; {{?}}
+    }
+  }
+{{?}}
+
+{{? $breakOnError }}
+  {{= $closingBraces }}
+  if ({{=$errs}} == errors) {
+{{?}}