style(bx-mobile): polish reimburse invoice attachment picker layout

Co-authored-by: Cursor <cursoragent@cursor.com>

bx-mobile/src/views/reimburse/ReimburseApplyPage.vue

@@ -1044,6 +1044,8 @@ onMounted(async () => {
   padding: 14px 16px;
   font-weight: 600;
   text-align: center;
+  border-bottom: 1px solid var(--border);
+  flex-shrink: 0;
 }
 .invoice-picker__body {
   flex: 1;
@@ -1078,6 +1080,9 @@ onMounted(async () => {
   background: #fff;
   text-align: left;
   overflow: hidden;
+  font: inherit;
+  color: inherit;
+  cursor: pointer;
 }
 .invoice-attach-card.is-selected {
   border-color: var(--primary);
@@ -1150,6 +1155,8 @@ onMounted(async () => {
 .invoice-picker__footer {
   margin-top: auto;
   padding: 12px 16px;
+  border-top: 1px solid var(--border);
+  flex-shrink: 0;
 }
 .advance-attachment-upload {
   display: flex;