fix(web,ui): adjust chat area height for better responsiveness

packages/ui/src/components/scroll-area/ScrollArea.vue

@@ -23,7 +23,7 @@ const delegatedProps = reactiveOmit(props, 'class')
   >
     <ScrollAreaViewport
       data-slot="scroll-area-viewport"
-      class="focus-visible:ring-ring/50 size-full rounded-[inherit] transition-[color,box-shadow] outline-none focus-visible:ring-[3px] focus-visible:outline-1"
+      class="focus-visible:ring-ring/50 size-full rounded-[inherit] transition-[color,box-shadow] outline-none focus-visible:ring-[3px] focus-visible:outline-1 flex flex-col [&>div:first-child]:flex-1"
     >
       <slot />
     </ScrollAreaViewport>

packages/web/src/pages/chat/index.vue

@@ -1,5 +1,5 @@
 <template>
-  <div class="flex h-[calc(100vh-calc(var(--spacing)*20))]">
+  <div class="flex h-full">
     <!-- Left: Bot sidebar -->
     <BotSidebar />