Refactor: Remove background task management and related hooks

- Deleted `useBackgroundTasks.ts` hook and its associated logic for managing background tasks.
- Removed `backgroundTaskManager.ts` service and all related task definitions and registrations.
- Cleaned up `Podfile.lock` and `package.json` to remove unused dependencies related to background tasks.
- Updated iOS project files to eliminate references to removed background task components.
- Added new background fetch identifier in `Info.plist` for future use.

app/mood/calendar.tsx

@@ -3,21 +3,19 @@ import { Colors } from '@/constants/Colors';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
 import { useColorScheme } from '@/hooks/useColorScheme';
 import { useMoodData } from '@/hooks/useMoodData';
-import { getMoodOptions, MoodOption } from '@/services/moodCheckins';
+import { getMoodOptions } from '@/services/moodCheckins';
 import { selectLatestMoodRecordByDate } from '@/store/moodSlice';
-import { Image } from 'react-native';
 import dayjs from 'dayjs';
 import { LinearGradient } from 'expo-linear-gradient';
 import { router, useFocusEffect, useLocalSearchParams } from 'expo-router';
 import React, { useCallback, useEffect, useRef, useState } from 'react';
 import {
-  Dimensions,
-  SafeAreaView,
+  Dimensions, Image, SafeAreaView,
   ScrollView,
   StyleSheet,
   Text,
   TouchableOpacity,
-  View,
+  View
 } from 'react-native';
 
 const { width } = Dimensions.get('window');
@@ -60,7 +58,7 @@ export default function MoodCalendarScreen() {
   // 使用 useRef 来存储函数引用，避免依赖循环
   const fetchMoodRecordsRef = useRef(fetchMoodRecords);
   const fetchMoodHistoryRecordsRef = useRef(fetchMoodHistoryRecords);
-  
+
   // 更新 ref 值
   fetchMoodRecordsRef.current = fetchMoodRecords;
   fetchMoodHistoryRecordsRef.current = fetchMoodHistoryRecords;
@@ -73,7 +71,7 @@ export default function MoodCalendarScreen() {
 
   // 使用 Redux store 中的数据
   const moodRecords = useAppSelector(state => state.mood.moodRecords);
-  
+
   // 获取选中日期的数据
   const selectedDateMood = useAppSelector(state => {
     if (!selectedDay) return null;
@@ -191,46 +189,30 @@ export default function MoodCalendarScreen() {
     const moodRecord = dayRecords.length > 0 ? dayRecords[0] : null;
 
     const isToday = day === new Date().getDate() &&
-                   month === new Date().getMonth() + 1 &&
-                   year === new Date().getFullYear();
+      month === new Date().getMonth() + 1 &&
+      year === new Date().getFullYear();
 
     if (moodRecord) {
       const mood = moodOptions.find(m => m.type === moodRecord.moodType);
-      const intensity = moodRecord.intensity;
-      const color = mood?.color || '#7a5af8';
-      
-      // 计算圆环的填充比例 (0-1)
-      const fillRatio = intensity / 10;
-      
+
       return (
-        <View style={isToday ? styles.todayMoodRingContainer : styles.moodRingContainer}>
-          <View style={[isToday ? styles.todayMoodRing : styles.moodRing, { borderColor: color }]}>
-            <View style={[
-              styles.moodRingFill,
-              {
-                backgroundColor: color,
-                height: `${fillRatio * 100}%`,
-                opacity: 0.7,
-              }
-            ]} />
-            <Text style={[styles.moodIntensityText, { color: '#fff', fontSize: isToday ? 7 : 8 }]}>
-              {intensity}
-            </Text>
+        <View style={isToday ? styles.todayMoodIconContainer : styles.moodIconContainer}>
+          <View style={styles.moodIcon}>
+            <Image
+              source={mood?.image}
+              style={styles.moodIconImage}
+            />
           </View>
         </View>
       );
     }
 
     return (
-      <View style={isToday ? styles.todayDefaultMoodRing : styles.defaultMoodRing}>
-        <View style={isToday ? styles.todayDefaultMoodRingBorder : styles.defaultMoodRingBorder} />
+      <View style={isToday ? styles.todayDefaultMoodIcon : styles.defaultMoodIcon}>
       </View>
     );
   };
 
-  // 使用统一的渐变背景色
-  const backgroundGradientColors = [colorTokens.backgroundGradientStart, colorTokens.backgroundGradientEnd] as const;
-
   return (
     <View style={styles.container}>
       <LinearGradient
@@ -242,7 +224,7 @@ export default function MoodCalendarScreen() {
       {/* 装饰性圆圈 */}
       <View style={styles.decorativeCircle1} />
       <View style={styles.decorativeCircle2} />
-      
+
       <SafeAreaView style={styles.safeArea}>
         <HeaderBar
           title="心情日历"
@@ -538,6 +520,20 @@ const styles = StyleSheet.create({
     shadowRadius: 2,
     elevation: 1,
   },
+  todayMoodIconContainer: {
+    position: 'absolute',
+    bottom: 1,
+    width: 20,
+    height: 20,
+    borderRadius: 10,
+    justifyContent: 'center',
+    alignItems: 'center',
+    shadowColor: '#7a5af8',
+    shadowOffset: { width: 0, height: 1 },
+    shadowOpacity: 0.2,
+    shadowRadius: 2,
+    elevation: 2,
+  },
   moodIcon: {
     width: 18,
     height: 18,
@@ -547,8 +543,8 @@ const styles = StyleSheet.create({
     alignItems: 'center',
   },
   moodIconImage: {
-    width: 18,
-    height: 18,
+    width: 28,
+    height: 28,
     borderRadius: 9,
   },
   defaultMoodIcon: {
@@ -564,10 +560,18 @@ const styles = StyleSheet.create({
     alignItems: 'center',
     backgroundColor: 'rgba(122,90,248,0.05)',
   },
-  defaultMoodEmoji: {
-    fontSize: 10,
-    opacity: 0.4,
-    color: '#7a5af8',
+  todayDefaultMoodIcon: {
+    position: 'absolute',
+    bottom: 1,
+    width: 20,
+    height: 20,
+    borderRadius: 10,
+    borderWidth: 1.5,
+    borderColor: 'rgba(122,90,248,0.4)',
+    borderStyle: 'dashed',
+    justifyContent: 'center',
+    alignItems: 'center',
+    backgroundColor: 'rgba(122,90,248,0.08)',
   },
   moodRingContainer: {
     position: 'absolute',
@@ -577,29 +581,7 @@ const styles = StyleSheet.create({
     justifyContent: 'center',
     alignItems: 'center',
   },
-  moodRing: {
-    width: 20,
-    height: 20,
-    borderRadius: 10,
-    borderWidth: 1.5,
-    justifyContent: 'flex-end',
-    alignItems: 'center',
-    overflow: 'hidden',
-    backgroundColor: 'rgba(255,255,255,0.95)',
-    shadowColor: '#000',
-    shadowOffset: { width: 0, height: 1 },
-    shadowOpacity: 0.1,
-    shadowRadius: 2,
-    elevation: 1,
-  },
-  moodRingFill: {
-    position: 'absolute',
-    bottom: 0,
-    left: 0,
-    right: 0,
-    borderBottomLeftRadius: 8,
-    borderBottomRightRadius: 8,
-  },
+
   moodIntensityText: {
     fontSize: 8,
     fontWeight: '800',
@@ -610,63 +592,8 @@ const styles = StyleSheet.create({
     textShadowOffset: { width: 0, height: 0.5 },
     textShadowRadius: 1,
   },
-  defaultMoodRing: {
-    position: 'absolute',
-    bottom: 2,
-    width: 22,
-    height: 22,
-    justifyContent: 'center',
-    alignItems: 'center',
-  },
-  defaultMoodRingBorder: {
-    width: 20,
-    height: 20,
-    borderRadius: 10,
-    borderWidth: 1.5,
-    borderColor: 'rgba(122,90,248,0.3)',
-    borderStyle: 'dashed',
-    backgroundColor: 'rgba(122,90,248,0.05)',
-  },
-  todayMoodRingContainer: {
-    position: 'absolute',
-    bottom: 1,
-    width: 20,
-    height: 20,
-    justifyContent: 'center',
-    alignItems: 'center',
-  },
-  todayMoodRing: {
-    width: 18,
-    height: 18,
-    borderRadius: 9,
-    borderWidth: 1.5,
-    justifyContent: 'flex-end',
-    alignItems: 'center',
-    overflow: 'hidden',
-    backgroundColor: 'rgba(255,255,255,0.95)',
-    shadowColor: '#7a5af8',
-    shadowOffset: { width: 0, height: 1 },
-    shadowOpacity: 0.2,
-    shadowRadius: 2,
-    elevation: 2,
-  },
-  todayDefaultMoodRing: {
-    position: 'absolute',
-    bottom: 1,
-    width: 20,
-    height: 20,
-    justifyContent: 'center',
-    alignItems: 'center',
-  },
-  todayDefaultMoodRingBorder: {
-    width: 18,
-    height: 18,
-    borderRadius: 9,
-    borderWidth: 1.5,
-    borderColor: 'rgba(122,90,248,0.4)',
-    borderStyle: 'dashed',
-    backgroundColor: 'rgba(122,90,248,0.08)',
-  },
+
+
   selectedDateSection: {
     backgroundColor: 'rgba(255,255,255,0.95)',
     margin: 16,
@@ -720,7 +647,7 @@ const styles = StyleSheet.create({
     width: 52,
     height: 52,
     borderRadius: 26,
-    backgroundColor: '#7a5af8',
+    backgroundColor: '#e9e7f1ff',
     justifyContent: 'center',
     alignItems: 'center',
     marginRight: 16,