feat(fasting): 新增轻断食功能模块

新增完整的轻断食功能，包括：
- 断食计划列表和详情页面，支持12-12、14-10、16-8、18-6四种计划
- 断食状态实时追踪和倒计时显示
- 自定义开始时间选择器
- 断食通知提醒功能
- Redux状态管理和数据持久化
- 新增tab导航入口和路由配置

services/fastingNotifications.ts

@@ -0,0 +1,162 @@
+import dayjs from 'dayjs';
+
+import { FastingPlan } from '@/constants/Fasting';
+import { FastingSchedule } from '@/store/fastingSlice';
+import {
+  clearFastingNotificationIds,
+  getFastingNotificationsRegistered,
+  loadStoredFastingNotificationIds,
+  saveFastingNotificationIds,
+  setFastingNotificationsRegistered,
+  FastingNotificationIds,
+} from '@/utils/fasting';
+import { getNotificationEnabled } from '@/utils/userPreferences';
+import { notificationService, NotificationTypes } from './notifications';
+
+const REMINDER_OFFSET_MINUTES = 10;
+
+const cancelNotificationIds = async (ids?: FastingNotificationIds) => {
+  if (!ids) return;
+  const { startId, endId } = ids;
+  try {
+    if (startId) {
+      await notificationService.cancelNotification(startId);
+    }
+  } catch (error) {
+    console.warn('取消断食开始提醒失败', error);
+  }
+
+  try {
+    if (endId) {
+      await notificationService.cancelNotification(endId);
+    }
+  } catch (error) {
+    console.warn('取消断食结束提醒失败', error);
+  }
+};
+
+export const ensureFastingNotificationsReady = async (): Promise<boolean> => {
+  try {
+    const notificationsEnabled = await getNotificationEnabled();
+    if (!notificationsEnabled) {
+      return false;
+    }
+
+    const registered = await getFastingNotificationsRegistered();
+    if (registered) {
+      return true;
+    }
+
+    const status = await notificationService.getPermissionStatus();
+    if (status !== 'granted') {
+      const requestStatus = await notificationService.requestPermission();
+      if (requestStatus !== 'granted') {
+        return false;
+      }
+    }
+
+    await setFastingNotificationsRegistered(true);
+    return true;
+  } catch (error) {
+    console.warn('初始化断食通知失败', error);
+    return false;
+  }
+};
+
+type ResyncOptions = {
+  schedule: FastingSchedule | null;
+  plan?: FastingPlan;
+  previousIds?: FastingNotificationIds;
+  enabled: boolean;
+};
+
+export const resyncFastingNotifications = async ({
+  schedule,
+  plan,
+  previousIds,
+  enabled,
+}: ResyncOptions): Promise<FastingNotificationIds> => {
+  const storedIds = previousIds ?? (await loadStoredFastingNotificationIds());
+  await cancelNotificationIds(storedIds);
+
+  if (!enabled) {
+    await setFastingNotificationsRegistered(false);
+    await clearFastingNotificationIds();
+    return {};
+  }
+
+  const preferenceEnabled = await getNotificationEnabled();
+  if (!preferenceEnabled) {
+    await setFastingNotificationsRegistered(false);
+    await clearFastingNotificationIds();
+    return {};
+  }
+
+  if (!schedule || !plan) {
+    await clearFastingNotificationIds();
+    return {};
+  }
+
+  const now = dayjs();
+  const start = dayjs(schedule.startISO);
+  const end = dayjs(schedule.endISO);
+
+  if (end.isBefore(now)) {
+    await clearFastingNotificationIds();
+    return {};
+  }
+
+  const notificationIds: FastingNotificationIds = {};
+
+  if (start.isAfter(now)) {
+    const preStart = start.subtract(REMINDER_OFFSET_MINUTES, 'minute');
+    const triggerMoment = preStart.isAfter(now) ? preStart : start;
+
+    try {
+      const startId = await notificationService.scheduleNotificationAtDate(
+        {
+          title: `${plan.title} 即将开始`,
+          body: preStart.isAfter(now)
+            ? `还有 ${REMINDER_OFFSET_MINUTES} 分钟就要进入断食窗口，喝一杯温水，准备迎接更轻盈的自己！`
+            : `现在开始 ${plan.title}，放下零食，给身体一次真正的休息时间。`,
+          data: {
+            type: NotificationTypes.FASTING_START,
+            planId: plan.id,
+          },
+          sound: true,
+          priority: 'high',
+        },
+        triggerMoment.toDate()
+      );
+      notificationIds.startId = startId;
+    } catch (error) {
+      console.error('安排断食开始通知失败', error);
+    }
+  }
+
+  if (end.isAfter(now)) {
+    try {
+      const endId = await notificationService.scheduleNotificationAtDate(
+        {
+          title: '补能时刻到啦',
+          body: `${plan.title} 已完成！用一顿高蛋白 + 低GI 的餐食奖励自己，让代谢持续高效运转。`,
+          data: {
+            type: NotificationTypes.FASTING_END,
+            planId: plan.id,
+          },
+          sound: true,
+          priority: 'high',
+        },
+        end.toDate()
+      );
+      notificationIds.endId = endId;
+    } catch (error) {
+      console.error('安排断食结束通知失败', error);
+    }
+  }
+
+  await saveFastingNotificationIds(notificationIds);
+  return notificationIds;
+};
+
+export type { FastingNotificationIds };

services/notifications.ts

@@ -1,3 +1,4 @@
+import { ROUTES } from '@/constants/Routes';
 import { getNotificationEnabled } from '@/utils/userPreferences';
 import * as Notifications from 'expo-notifications';
 import { router } from 'expo-router';
@@ -5,7 +6,6 @@ import { router } from 'expo-router';
 // 配置通知处理方式
 Notifications.setNotificationHandler({
   handleNotification: async () => ({
-    shouldShowAlert: true,
     shouldPlaySound: true,
     shouldSetBadge: true,
     shouldShowBanner: true,
@@ -179,6 +179,8 @@ export class NotificationService {
       if (data?.url) {
         router.push(data.url as any);
       }
+    } else if (data?.type === NotificationTypes.FASTING_START || data?.type === NotificationTypes.FASTING_END) {
+      router.push(ROUTES.TAB_FASTING as any);
     } else if (data?.type === NotificationTypes.WORKOUT_COMPLETION) {
       // 处理锻炼完成通知
       console.log('用户点击了锻炼完成通知', data);
@@ -517,6 +519,8 @@ export const NotificationTypes = {
   REGULAR_WATER_REMINDER: 'regular_water_reminder',
   CHALLENGE_ENCOURAGEMENT: 'challenge_encouragement',
   WORKOUT_COMPLETION: 'workout_completion',
+  FASTING_START: 'fasting_start',
+  FASTING_END: 'fasting_end',
 } as const;
 
 // 便捷方法