feat: render announcements on dashboard

server/src/routes/announcement.ts

@@ -28,7 +28,14 @@ export const announcementRoutes: FastifyPluginAsync = async(server) => {
       take: 10,
     });
     return await reply.status(200).type("application/json").
-      send(announcements);
+      send(announcements.map((announcement) => {
+        return {
+          content:   announcement.content,
+          createdAt: announcement.createdAt,
+          title:     announcement.title,
+          type:      announcement.type,
+        };
+      }));
   });
 
   // eslint-disable-next-line @typescript-eslint/naming-convention -- Fastify requires Body instead of body.