✨ feat: 完整应用重构 - 优化界面架构与用户体验

主要变更：
- 重构应用界面：优化首页、登录、认证流程
- 新增用户档案模块：包含完整的档案管理组件
- 优化路由结构：重新组织页面布局和导航
- 改进API集成：新增活动、内容分类等API模块
- 删除冗余组件：清理不必要的文件和依赖

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

utils/profile-data.ts

@@ -0,0 +1,73 @@
+import type { ImageSourcePropType } from 'react-native';
+
+export type IdentityStat = {
+  key: string;
+  label: string;
+  value: number;
+};
+
+const STAT_BLUEPRINT: IdentityStat[] = [
+  { key: 'likes', label: 'likes', value: 0 },
+  { key: 'posts', label: 'posts', value: 0 },
+  { key: 'views', label: 'views', value: 0 },
+];
+
+export function createStats(user: unknown): IdentityStat[] {
+  const source = (user as Record<string, unknown>) ?? {};
+  return STAT_BLUEPRINT.map(stat => ({
+    ...stat,
+    value: deriveNumericValue(source[stat.key]),
+  }));
+}
+
+export function deriveDisplayName(user: unknown): string | null {
+  if (!user || typeof user !== 'object') {
+    return null;
+  }
+  const data = user as Record<string, unknown>;
+  return ensureString(data.username) ?? ensureString(data.name) ?? null;
+}
+
+export function deriveAvatarSource(user: unknown): ImageSourcePropType | undefined {
+  if (!user || typeof user !== 'object') {
+    return undefined;
+  }
+  const image = ensureString((user as Record<string, unknown>).image);
+  if (!image) {
+    return undefined;
+  }
+  return { uri: image };
+}
+
+export function deriveNumericValue(value: unknown): number {
+  if (typeof value === 'number' && Number.isFinite(value)) {
+    return value;
+  }
+  if (typeof value === 'string') {
+    const parsed = Number(value);
+    if (Number.isFinite(parsed)) {
+      return parsed;
+    }
+  }
+  return 0;
+}
+
+export function deriveInitials(name: string): string {
+  const tokens = name
+    .replace(/[_-]+/g, ' ')
+    .split(/\s+/)
+    .filter(Boolean);
+  if (tokens.length === 0) {
+    return 'AI';
+  }
+  const initials = tokens.slice(0, 2).map(part => part[0]?.toUpperCase() ?? '');
+  return initials.join('') || tokens[0][0]?.toUpperCase() || 'AI';
+}
+
+function ensureString(value: unknown): string | null {
+  if (typeof value !== 'string') {
+    return null;
+  }
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : null;
+}