完善概览页，实现公告查询展示，引入 recharts 展示取用数据

src/lib/models.ts

@@ -123,3 +123,15 @@ export type Channel = {
   created_at: Date
   updated_at: Date
 }
+
+export type Announcement = {
+  id: number
+  title: string
+  content: string
+  type: number
+  status: number
+  pin: boolean
+  sort: number
+  created_at: Date
+  updated_at: Date
+}