refactor(layout): update BasicLayout and LayoutHeader styling with ant design improvements

- Replace ant-design-vue message with vue-sonner toast notifications
- Remove LayoutHeader component import from BasicLayout
- Update CSS classes for better styling consistency
- Adjust padding and spacing in layout components
- Modify shadow and overflow properties in task management views
- Add hidden class utility for element visibility control

frontend/app/web-gold/src/views/system/task-management/digital-human-task/index.vue

@@ -407,18 +407,16 @@ onMounted(fetchList)
   padding: var(--space-4);
   background: var(--color-bg-card);
   border-radius: var(--radius-lg);
-  box-shadow: var(--shadow-sm);
 }
 
 .task-page__content {
   flex: 1;
-  overflow: auto;
+  overflow: hidden;
   background: var(--color-bg-card);
   border-radius: var(--radius-lg);
   padding: var(--space-4);
   display: flex;
   flex-direction: column;
-  box-shadow: var(--shadow-sm);
 }
 
 .batch-actions {

frontend/app/web-gold/src/views/system/task-management/layout/TaskLayout.vue

@@ -8,9 +8,7 @@
             v-for="item in NAV_ITEMS"
             :key="item.type"
             :value="item.type"
-            class="h-10 px-4 gap-2 rounded-lg transition-all
-              data-[state=active]:bg-primary data-[state=active]:text-white data-[state=active]:shadow-sm
-              data-[state=inactive]:text-muted-foreground data-[state=inactive]:hover:text-foreground data-[state=inactive]:hover:bg-muted"
+            class="h-10 px-4 gap-2 rounded-lg transition-all data-[state=active]:bg-foreground data-[state=active]:!text-white data-[state=active]:shadow-sm data-[state=inactive]:text-muted-foreground data-[state=inactive]:hover:text-foreground data-[state=inactive]:hover:bg-muted"
           >
             <Icon :icon="item.icon" class="size-4" />
             <span>{{ item.label }}</span>
@@ -82,14 +80,12 @@ const currentComponent = computed(() => {
 .task-layout__header {
   flex-shrink: 0;
   padding: 0 var(--space-4);
-  border-bottom: 1px solid var(--color-border);
   background: var(--color-bg-card);
 }
 
 .task-layout__content {
   flex: 1;
   overflow: auto;
-  background: var(--color-bg-page);
 }
 
 .fade-enter-active,

frontend/app/web-gold/src/views/system/task-management/mix-task/index.vue

@@ -72,6 +72,7 @@
           :disabled="!hasDownloadableSelected"
           :loading="batchDownloading"
           size="sm"
+          class="text-white"
           @click="handleBatchDownloadSelected"
         >
           <Icon icon="lucide:download" class="mr-1 size-4" />
@@ -630,7 +631,6 @@ onMounted(fetchList)
   padding: var(--space-4);
   background: var(--color-bg-card);
   border-radius: var(--radius-lg);
-  box-shadow: var(--shadow-sm);
 }
 
 .task-page__content {
@@ -641,7 +641,6 @@ onMounted(fetchList)
   padding: var(--space-4);
   display: flex;
   flex-direction: column;
-  box-shadow: var(--shadow-sm);
 }
 
 .batch-toolbar {