fix: resolve homepage 404 and add mock data for user portrait

Add landing page, fix type errors, mark dynamic API route, and refactor user portrait page.

Co-authored-by: null <4804959+fnvtk@users.noreply.github.com>

lib/mock-users.ts

@@ -15,6 +15,49 @@ export interface User {
   lastActiveAt: string
 }
 
+export interface MockUser {
+  id: string
+  name: string
+  nickname?: string
+  avatar?: string
+  tags: string[]
+  lastActive: string
+  city?: string
+  valueScore?: number
+}
+
+export const MOCK_USERS: MockUser[] = [
+  {
+    id: "u_1001",
+    name: "张三",
+    nickname: "技术控",
+    avatar: "/user-avatar-zhangsan.png",
+    tags: ["技术爱好者", "夜猫子"],
+    lastActive: "2025-08-01T10:20:00Z",
+    city: "深圳",
+    valueScore: 86,
+  },
+  {
+    id: "u_1002",
+    name: "李四",
+    nickname: "内容创作者",
+    avatar: "/user-avatar-lisi.png",
+    tags: ["短视频", "自动化工具"],
+    lastActive: "2025-08-06T14:30:00Z",
+    city: "广州",
+    valueScore: 72,
+  },
+  {
+    id: "u_1003",
+    name: "王雷",
+    avatar: "/avatar-wanglei.png",
+    tags: ["效率提升"],
+    lastActive: "2025-08-07T08:05:00Z",
+    city: "成都",
+    valueScore: 64,
+  },
+]
+
 const familyNames = ['张','李','王','赵','刘','陈','杨','黄','周','吴','徐','孙','胡','朱','高','林','何','郭','马','罗']
 const givenNames = ['伟','芳','娜','敏','静','秀英','丽','强','磊','军','洋','艳','勇','杰','娟','涛','明','超','霞','平','俊','凯','佳','鑫','鹏','晨','倩','颖','梅','慧','雪','宇','涵','宁','璐','龙','震','航','璟','钰']
 const tagPool = ['高价值','近7日活跃','新客','回流','社群达人','潜在复购','高互动','低客单','私域粉','公众号粉']