feat: 添加会话列表和搜索功能，重构聊天界面组件

features/im/mocks/mock-conversations.ts

@@ -0,0 +1,30 @@
+import type { ConversationItem } from "@/features/im/types/conversation";
+
+export const mockConversations: ConversationItem[] = [
+  {
+    id: "system",
+    kind: "system",
+    title: "系统消息",
+    preview: "[系统消息]",
+    timeLabel: "昨天 20:12",
+  },
+  {
+    id: "admin",
+    kind: "direct",
+    title: "Admin",
+    preview: "这是一条聊天消息，很长的聊天消息",
+    timeLabel: "21分钟前",
+    avatarUrl:
+      "https://images.unsplash.com/photo-1613070120286-98b11cdb9f8f?auto=format&fit=crop&w=120&q=80",
+    unreadCount: 2,
+  },
+  {
+    id: "zhangsan",
+    kind: "direct",
+    title: "张三",
+    preview: "你好呀~~~",
+    timeLabel: "21分钟前",
+    avatarUrl:
+      "https://images.unsplash.com/photo-1524504388940-b1c1722653e1?auto=format&fit=crop&w=120&q=80",
+  },
+];