支持在线时间跨天并优化发布与筛选体验

允许在线时段 end 早于 start 表示跨天，统一展示「次日」文案；修复移动端价格区间清空后被 sessionStorage 回写；优化 PC/移动端在线时间控件密度与通栏展示。

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

@@ -207,52 +207,127 @@
   gap: 8px;
 }
 
-.online-time-field :deep(.van-field__control) {
-  min-height: 32px;
+/* 在线时间：通栏紧凑布局，高度贴近其它 publish-field */
+.online-time-block {
+  margin-bottom: 8px;
+  padding: 10px 12px;
+  border-radius: 8px;
+  background: #f8fafc;
 }
 
-.online-time-controls {
+.online-time-head {
   display: flex;
-  flex-wrap: wrap;
   align-items: center;
+  justify-content: space-between;
+  gap: 8px;
+  margin-bottom: 8px;
+}
+
+.online-time-title {
+  display: flex;
+  align-items: center;
+  gap: 2px;
+  color: #30343a;
+  font-size: 13px;
+  font-weight: 600;
+  line-height: 1.2;
+}
+
+.online-time-title .req {
+  color: #ee0a24;
+  font-weight: 800;
+}
+
+.online-time-allday {
+  flex-shrink: 0;
+  min-height: 28px !important;
+  padding: 0 12px !important;
+  font-size: 12px !important;
+}
+
+.online-time-grid {
+  display: grid;
+  grid-template-columns: 1fr 1fr;
   gap: 8px;
   width: 100%;
 }
 
-.online-time-range {
+.online-time-pick {
   display: flex;
-  flex: 1;
+  flex-direction: row;
   align-items: center;
+  justify-content: space-between;
   gap: 6px;
+  width: 100%;
   min-width: 0;
-}
-
-.online-time-input {
-  flex: 1;
-  min-width: 0;
-  height: 32px;
-  padding: 0 10px;
+  min-height: 36px;
+  padding: 6px 10px;
   border: 1px solid #e2e8f0;
   border-radius: 999px;
-  background: #f8fafc;
-  color: #1e293b;
-  font-size: 13px;
-  font-weight: 600;
-  font-variant-numeric: tabular-nums;
+  background: #fff;
+  text-align: left;
+  cursor: pointer;
+  transition:
+    border-color 0.15s ease,
+    box-shadow 0.15s ease;
 }
 
-.online-time-input:focus {
-  outline: none;
+.online-time-pick:active {
   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;
+.online-time-label {
+  display: flex;
+  align-items: center;
+  gap: 3px;
+  flex-shrink: 0;
+  color: #8a94a6;
+  font-size: 11px;
+  font-weight: 600;
+  line-height: 1.2;
+}
+
+.online-time-label em {
+  font-style: normal;
+  padding: 0 4px;
+  border-radius: 999px;
+  background: rgba(255, 106, 0, 0.1);
+  color: #ff6a00;
+  font-size: 10px;
+  font-weight: 800;
+}
+
+.online-time-pick strong {
+  min-width: 0;
+  color: #20242a;
+  font-size: 15px;
   font-weight: 700;
+  font-variant-numeric: tabular-nums;
+  letter-spacing: 0.01em;
+  line-height: 1.2;
+  text-align: right;
+}
+
+.online-time-pick strong.placeholder {
+  color: #94a3b8;
+  font-size: 13px;
+  font-weight: 600;
+}
+
+.online-time-summary {
+  margin: 6px 0 0;
+  color: #64748b;
+  font-size: 11px;
+  font-weight: 500;
+  line-height: 1.35;
+}
+
+.online-time-hint {
+  margin: 6px 0 0;
+  color: #858c96;
+  font-size: 11px;
+  line-height: 1.45;
 }
 
 .level-panel {