fix(admin): unblock post list save and permissions schema endpoints

Align post_list.list pagination values with PHP (numbered/load_more/infinite)
so SchemaPage saves no longer 422 on 分页模式. Stop permissions schema build
from fatally calling missing build_cap_matrix_groups() when loading
login/moderation sections, normalize moderation dependsOn objects, and skip
notice-only fields in schema field collection.

inc/classes/admin/class-aksrt-admin-schema-provider.php

@@ -333,7 +333,17 @@ class AKSRT_Admin_Schema_Provider {
     private function get_all_fields(array $schema): array {
         $fields = [];
         foreach ($schema['groups'] ?? [] as $group) {
+            if (!is_array($group)) {
+                continue;
+            }
             foreach ($group['fields'] ?? [] as $field) {
+                if (!is_array($field) || empty($field['key'])) {
+                    continue;
+                }
+                // Notice/help-only rows are UI chrome, not stored settings keys.
+                if (($field['type'] ?? '') === 'notice') {
+                    continue;
+                }
                 $fields[] = $field;
             }
         }