优化首页返回定位与发布在线时间表单

移动端首页用列表缓存和内部滚动恢复浏览位置；发布页在线时间改为全天+起止时间单行布局。

frontend/src/features/seller/views/MobileSellerListingCreateView.css

@@ -200,24 +200,58 @@
   cursor: not-allowed;
 }
 
-.time-row,
 .result-grid {
   display: grid;
   grid-template-columns: 1fr;
   gap: 8px;
 }
 
-.time-field-group {
-  display: grid;
+.online-time-field :deep(.van-field__control) {
+  min-height: 32px;
+}
+
+.online-time-controls {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 8px;
+  width: 100%;
+}
+
+.online-time-range {
+  display: flex;
+  flex: 1;
+  align-items: center;
   gap: 6px;
+  min-width: 0;
 }
 
-.time-field-group .publish-field {
-  margin-bottom: 0;
+.online-time-input {
+  flex: 1;
+  min-width: 0;
+  height: 32px;
+  padding: 0 10px;
+  border: 1px solid #e2e8f0;
+  border-radius: 999px;
+  background: #f8fafc;
+  color: #1e293b;
+  font-size: 13px;
+  font-weight: 600;
+  font-variant-numeric: tabular-nums;
 }
 
-.time-preset-chips {
-  padding: 0 2px 4px;
+.online-time-input:focus {
+  outline: none;
+  border-color: #ffb074;
+  background: #fff;
+  box-shadow: 0 0 0 3px rgba(255, 106, 0, 0.1);
+}
+
+.online-time-sep {
+  flex: 0 0 auto;
+  color: #94a3b8;
+  font-size: 12px;
+  font-weight: 700;
 }
 
 .level-panel {
@@ -832,11 +866,7 @@
   background: #ff6a00 !important;
 }
 
-@media (min-width: 430px) {
-  .time-row {
-    grid-template-columns: 1fr 1fr;
-  }
-}
+
 
 @media (max-width: 370px) {
   .level-options,