fix: 兼容 Chrome 90 前端运行环境

- 为管理端与用户中心补齐旧浏览器运行时 API 和回归测试

- 增加现代 CSS 与选择器降级，保持现有界面效果

- 固定 Chrome 90 构建目标并补充兼容依赖

easyflow-ui-admin/packages/tinyflow-ui/src/components/base/mixed-input.svelte

@@ -164,7 +164,7 @@
         </div>
 
         {#snippet floating()}
-             <div class="tf-mixed-dropdown nopan nodrag nowheel">
+             <div class="tf-mixed-dropdown nopan nodrag nowheel {hoveredItem?.children?.length ? 'has-secondary' : ''}">
                   <div class="tf-mixed-list tf-mixed-primary-list">
                       {#each refOptions as item}
                           <button class="tf-mixed-item {hoveredItem?.value === item.value ? 'active' : ''}"
@@ -391,7 +391,7 @@
   }
   .tf-mixed-list { display: flex; flex-direction: column; padding: 8px; overflow-y: auto; }
   .tf-mixed-primary-list { width: 100%; flex-shrink: 0; background: var(--tf-bg-surface-alt); }
-  .tf-mixed-dropdown:has(.tf-mixed-secondary-list) .tf-mixed-primary-list { width: auto; min-width: 180px; }
+  .tf-mixed-dropdown.has-secondary .tf-mixed-primary-list { width: auto; min-width: 180px; }
   .tf-mixed-secondary-list { min-width: 220px; background: var(--tf-bg-surface); padding: 12px; border-left: 1px solid var(--tf-bg-muted); animation: slideIn 0.2s ease-out; box-sizing: border-box; }
 
   @keyframes slideIn { from { opacity: 0; transform: translateX(-10px); } to { opacity: 1; transform: translateX(0); } }

easyflow-ui-admin/packages/tinyflow-ui/src/components/base/select.svelte

@@ -296,7 +296,7 @@
                     </div>
                 </div>
             {:else}
-                <div class="tf-select-wrapper nopan nodrag nowheel">
+                <div class="tf-select-wrapper nopan nodrag nowheel {hoveredItem?.children?.length ? 'has-secondary' : ''}">
                     <!-- 一级列表：节点/分类 -->
                     <div class="tf-select-list tf-select-primary-list">
                         {#each items as item}
@@ -580,7 +580,7 @@
     }
 
     /* When a secondary list is open, we fix the primary list to 100% of the input's width (done via absolute positioning or just keeping it wide enough) */
-    .tf-select-wrapper:has(.tf-select-secondary-list) &.tf-select-primary-list {
+    .tf-select-wrapper.has-secondary &.tf-select-primary-list {
         /* Let it take the width of the input minus borders/paddings if needed, but minWidth handles it mostly */
         width: auto; 
         min-width: 160px;