feat(ui): 重构高级搜索组件并优化布局

- 重构 AiPullDown 组件，使用 v-model 实现双向绑定
- 优化 AiSearchBar 组件样式和布局
- 调整 AiPage 组件中的滚动条样式

ui/packages/basic/AiPullDown.vue

@@ -14,8 +14,11 @@
 export default {
   name: "AiPullDown",
   props: {
-    target: String,
-    height: {default: 4},
+    value: Boolean,
+  },
+  model: {
+    prop: 'value',
+    event: 'expand'
   },
   data() {
     return {
@@ -25,32 +28,34 @@ export default {
   methods: {
     handleExpand() {
       this.expand = !this.expand
-      if (this.target) {
-
-      } else this.$emit('change', this.expandStyle)
     }
   },
   computed: {
     btnText() {
-      return this.expand ? '收起高级搜索' : '展开高级搜索'
-    },
-    expandStyle() {
-      let initStyle = {overflow: 'hidden', height: `${this.height}px`}
-      this.expand && (initStyle.height = "auto")
-      return initStyle
+      return this.expand ? '收起' : '展开'
     },
     expandIcon() {
       return this.expand ? 'iconfont iconDouble_Up' : 'iconfont iconDouble_Down'
     }
   },
-  mounted() {
-    this.$emit("change", this.expandStyle)
+  watch: {
+    expand: {
+      immediate: true, handler(v) {
+        this.$emit('expand', v)
+      }
+    }
   }
 }
 </script>
 <style lang="scss" scoped>
 .AiPullDown {
   display: flex;
+  position: absolute;
+  left: 0;
+  right: 0;
+  bottom: 24px;
+  transform: translateY(100%);
+  background-color: #fff;
 
   .line {
     flex: 1;