fix(admin): accept multi-value 发布类型 on header-nav save

header_newposts_types is multi-select but PHP schema used type=select,
so validate() rejected arrays with 422. Use checkbox and allow
select+multiple arrays in SchemaProvider.

src/AKSRT/Admin/SchemaProvider.php

@@ -181,13 +181,26 @@ class SchemaProvider {
 
                 if (in_array($type, ['select', 'radio'], true) && !empty($field['options'])) {
                     $valid_values = array_column($field['options'], 'value');
-                    if (!in_array($value, $valid_values, true)) {
+                    // Multi-select: accept array values when schema.multiple is set
+                    // (legacy / SPA may still use type=select multiple).
+                    if (!empty($field['multiple']) && is_array($value)) {
+                        foreach ($value as $item) {
+                            if (!in_array($item, $valid_values, true)) {
+                                $errors[] = sprintf('%s has an invalid value', $field['label'] ?? $key);
+                                break;
+                            }
+                        }
+                    } elseif (!in_array($value, $valid_values, true)) {
                         $errors[] = sprintf('%s has an invalid value', $field['label'] ?? $key);
                     }
                 }
 
                 if ($type === 'checkbox' && !empty($field['options'])) {
                     $valid_values = array_column($field['options'], 'value');
+                    if (!is_array($value)) {
+                        $errors[] = sprintf('%s must be an array', $field['label'] ?? $key);
+                        continue;
+                    }
                     foreach ((array) $value as $item) {
                         if (!in_array($item, $valid_values, true)) {
                             $errors[] = sprintf('%s has an invalid value', $field['label'] ?? $key);