feat: 集成 Redux 状态管理和用户目标管理功能

- 添加 Redux 状态管理，支持用户登录和个人信息的持久化
- 新增目标管理页面，允许用户设置每日卡路里和步数目标
- 更新首页，移除旧的活动展示，改为固定的热点功能卡片
- 修改布局以适应新功能的展示和交互
- 更新依赖，添加 @reduxjs/toolkit 和 react-redux 库以支持状态管理
- 新增 API 服务模块，处理与后端的交互

services/api.ts

@@ -0,0 +1,88 @@
+import { buildApiUrl } from '@/constants/Api';
+import AsyncStorage from '@react-native-async-storage/async-storage';
+
+type HttpMethod = 'GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE';
+
+let inMemoryToken: string | null = null;
+
+export async function setAuthToken(token: string | null): Promise<void> {
+  inMemoryToken = token;
+}
+
+export function getAuthToken(): string | null {
+  return inMemoryToken;
+}
+
+export type ApiRequestOptions = {
+  method?: HttpMethod;
+  headers?: Record<string, string>;
+  body?: any;
+  signal?: AbortSignal;
+};
+
+export type ApiResponse<T> = {
+  data: T;
+};
+
+async function doFetch<T>(path: string, options: ApiRequestOptions = {}): Promise<T> {
+  const url = buildApiUrl(path);
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    ...(options.headers || {}),
+  };
+
+  const token = getAuthToken();
+  if (token) {
+    headers['Authorization'] = `Bearer ${token}`;
+  }
+
+  const response = await fetch(url, {
+    method: options.method ?? 'GET',
+    headers,
+    body: options.body != null ? JSON.stringify(options.body) : undefined,
+    signal: options.signal,
+  });
+
+  const text = await response.text();
+  let json: any = null;
+  try {
+    json = text ? JSON.parse(text) : null;
+  } catch {
+    // 非 JSON 响应
+  }
+
+  if (!response.ok) {
+    const errorMessage = (json && (json.message || json.error)) || `HTTP ${response.status}`;
+    const error = new Error(errorMessage);
+    // @ts-expect-error augment
+    error.status = response.status;
+    throw error;
+  }
+
+  // 支持后端返回 { data: ... } 或直接返回对象
+  return (json && (json.data ?? json)) as T;
+}
+
+export const api = {
+  get: <T>(path: string, options?: ApiRequestOptions) => doFetch<T>(path, { ...options, method: 'GET' }),
+  post: <T>(path: string, body?: any, options?: ApiRequestOptions) => doFetch<T>(path, { ...options, method: 'POST', body }),
+  put: <T>(path: string, body?: any, options?: ApiRequestOptions) => doFetch<T>(path, { ...options, method: 'PUT', body }),
+  patch: <T>(path: string, body?: any, options?: ApiRequestOptions) => doFetch<T>(path, { ...options, method: 'PATCH', body }),
+  delete: <T>(path: string, options?: ApiRequestOptions) => doFetch<T>(path, { ...options, method: 'DELETE' }),
+};
+
+export const STORAGE_KEYS = {
+  authToken: '@auth_token',
+  userProfile: '@user_profile',
+} as const;
+
+export async function loadPersistedToken(): Promise<string | null> {
+  try {
+    const t = await AsyncStorage.getItem(STORAGE_KEYS.authToken);
+    return t || null;
+  } catch {
+    return null;
+  }
+}
+
+