📱 feat(pricing-header): show only search/copy/filter on mobile; hide vendor intro

- Mobile (isMobile=true): render SearchActions (search, copy, filter) only; hide vendor intro card
- Keep PricingFilterModal available on mobile for filtering
- Desktop/Non-mobile: unchanged behavior (vendor intro remains visible)
- Improves small-screen UX by reducing visual clutter and prioritizing primary actions

Files:
- web/src/components/table/model-pricing/layout/header/PricingTopSection.jsx

Notes:
- Added `SearchActions` import and conditional rendering
- No breaking changes; no styling changes required

web/src/index.css

@@ -775,6 +775,7 @@ html.dark .with-pastel-balls::before {
 }
 
 /* ==================== semi-ui 组件自定义样式 ==================== */
-.semi-card-header {
+.semi-card-header,
+.semi-card-body {
   padding: 10px !important;
 }