feat(admin): polish badge, OAuth and payment gateway settings UX

- Badge page: rewrite as collapsible sortable category/item cards with
  preset medal icon picker, dirty-tracked save bar and duplicate slug check;
  drop user_badge_* dual-read and legacy name/icon_url fallbacks
- OAuth: provider config groups collapsible, expanded when provider is on;
  clogin visibility moved to group-level dependsOn
- Gateway: expandWhen accepts dependsOn-style rules; select-gated groups no
  longer always expand ('null' was truthy); mark five gateway secrets as
  secret/password in JS and PHP; class-based notice list styling
- Remove unused UserRuntime::parse_badge_dictionary

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/admin/src/components/form/AksField.vue

@@ -948,6 +948,12 @@ function updateRepeaterItem(index, fieldKey, value) {
   line-height: 1.6;
 }
 
+.aksrt-field__content :deep(ul) {
+  margin: 0;
+  padding-left: 18px;
+  line-height: 1.9;
+}
+
 /* Mobile */
 @media (max-width: 768px) {
   .aksrt-field__link,

assets/admin/src/components/form/AksFormRenderer.vue

@@ -248,16 +248,21 @@ function isGroupVisible(group) {
   return matchDependsOn(group.dependsOn)
 }
 
+/**
+ * expandWhen 与 dependsOn 同语法（表单 key 字符串或规则对象），规则成立时分组默认展开。
+ * 下拉值如 'null' 也是真值，所以按选项判断的分组要写规则对象，不能只写 key。
+ */
+function isGroupExpanded(group) {
+  return matchDependsOn(group.expandWhen)
+}
+
 /**
  * Collapse preference for a group.
- * - expandWhen: form key; when truthy, start expanded (channel just enabled → open form)
+ * - expandWhen: rule; when matched, start expanded (channel just enabled → open form)
  * - defaultCollapsed: static default
  */
 function resolveGroupCollapsed(group) {
-  if (group.expandWhen) {
-    const on = !!props.formData?.[group.expandWhen]
-    return !on
-  }
+  if (group.expandWhen) return !isGroupExpanded(group)
   return !!group.defaultCollapsed
 }
 
@@ -265,7 +270,7 @@ function resolveGroupCollapsed(group) {
 function groupKey(group) {
   const base = group.key || group.title || 'group'
   if (group.expandWhen) {
-    return `${base}:${props.formData?.[group.expandWhen] ? 'on' : 'off'}`
+    return `${base}:${isGroupExpanded(group) ? 'on' : 'off'}`
   }
   return base
 }