feat(nav): finish remaining parity gaps (image_select, AJAX search, senior UI)

- Layout image_select previews (zibll PNGs under assets/images/header-layout)
- Localize aksrtAdminData.themeUri for admin SPA asset URLs
- Layout-2 inline search AJAX suggestions via aksrt_search_suggestions
- Appearance→Menus visual senior submenu editor (cards/columns)
- Acceptance checklist + automated source contract report

src/AKSRT/Admin/Schema/SchemaPageDisplay.php

@@ -31,15 +31,8 @@ class SchemaPageDisplay {
                             ['key' => 'header_scroll_down_hide', 'label' => '下滑隐藏导航栏', 'type' => 'switch', 'default' => true],
                         ]],
                         ['key' => 'layout-type', 'title' => '布局类型', 'fields' => [
-                            ['key' => 'header_layout', 'label' => '桌面端布局', 'type' => 'radio', 'default' => '1', 'options' => [
-                                ['label' => '布局 1（经典）', 'value' => '1'],
-                                ['label' => '布局 2（内联搜索）', 'value' => '2'],
-                                ['label' => '布局 3（紧凑）', 'value' => '3'],
-                            ]],
-                            ['key' => 'mobile_header_layout', 'label' => '移动端布局', 'type' => 'radio', 'default' => 'center', 'options' => [
-                                ['label' => '居中（含搜索按钮）', 'value' => 'center'],
-                                ['label' => '靠左', 'value' => 'left'],
-                            ]],
+                            ['key' => 'header_layout', 'label' => '桌面端布局', 'type' => 'image_select', 'default' => '1', 'options' => self::header_layout_options()],
+                            ['key' => 'mobile_header_layout', 'label' => '移动端布局', 'type' => 'image_select', 'default' => 'center', 'options' => self::mobile_header_layout_options()],
                             ['key' => 'mobile_navbar_align', 'label' => '移动端菜单方向', 'type' => 'radio', 'default' => 'left', 'options' => [
                                 ['label' => '顶部（关闭手势）', 'value' => 'top'],
                                 ['label' => '左侧滑出', 'value' => 'left'],
@@ -532,4 +525,24 @@ class SchemaPageDisplay {
             ],
         ];
     }
+
+    /** @return list<array{label:string,value:string,image:string}> */
+    private static function header_layout_options(): array {
+        $base = defined('AKSRT_URI') ? trailingslashit(AKSRT_URI) . 'assets/images/header-layout/' : '';
+        return [
+            ['label' => '布局 1（经典）', 'value' => '1', 'image' => $base . 'header_layout_1.png'],
+            ['label' => '布局 2（内联搜索）', 'value' => '2', 'image' => $base . 'header_layout_2.png'],
+            ['label' => '布局 3（紧凑）', 'value' => '3', 'image' => $base . 'header_layout_3.png'],
+        ];
+    }
+
+    /** @return list<array{label:string,value:string,image:string}> */
+    private static function mobile_header_layout_options(): array {
+        $base = defined('AKSRT_URI') ? trailingslashit(AKSRT_URI) . 'assets/images/header-layout/' : '';
+        return [
+            ['label' => '居中（含搜索按钮）', 'value' => 'center', 'image' => $base . 'mobile_header_layout_center.png'],
+            ['label' => '靠左', 'value' => 'left', 'image' => $base . 'mobile_header_layout_left.png'],
+        ];
+    }
+
 }