style(ui): enhance hover states for interactive elements

Improve user experience by adding consistent hover effects to clickable elements:
- ChatHistory "New Conversation" button now shows background and border color changes
- TaskCenter task items get subtle background change on hover
Both changes maintain visual consistency with the application's color scheme.

src/pages/home/TaskCenter.vue

@@ -9,7 +9,8 @@
 
         <div class="grid grid-cols-2 gap-4 max-[800px]:grid-cols-1">
             <div v-for="item in taskList" :key="item.id" class="flex gap-3 items-start p-3.5
-                  rounded-[10px] border border-[#dfeaf6] bg-white cursor-pointer" @click="handleTaskItem(item)">
+                  rounded-[10px] border border-[#dfeaf6] bg-white cursor-pointer hover:bg-[#F5F7FA]"
+                @click="handleTaskItem(item)">
                 <div class="w-11 h-11 bg-[#EFF6FF] rounded-lg
                     border border-dashed border-[#9fc0e8]
                     flex items-center justify-center