Refactor components and enhance background task management

- Updated font sizes and weights in BasalMetabolismCard, MoodCard, HealthDataCard, and NutritionRadarCard for improved readability.
- Removed loading state from MoodCard to simplify the component.
- Adjusted styles in WeightHistoryCard for better layout and spacing.
- Integrated expo-background-fetch for improved background task handling.
- Updated Info.plist to include background fetch capability.
- Enhanced background task registration and execution logic in backgroundTaskManager.
- Added debug function to manually trigger background task execution for testing purposes.

app/(tabs)/statistics.tsx

@@ -149,7 +149,7 @@ export default function ExploreScreen() {
     });
   }, [userProfile]);
 
-  const { registerTask } = useBackgroundTasks();
+  const { registerTask, isInitialized } = useBackgroundTasks();
   // 心情相关状态
   const dispatch = useAppDispatch();
   const [isMoodLoading, setIsMoodLoading] = useState(false);
@@ -416,27 +416,34 @@ export default function ExploreScreen() {
   }, [loadAllData, currentSelectedDate]);
 
   useEffect(() => {
-    // 注册后台任务 - 只处理健康数据和压力检查
-    registerTask({
-      id: 'health-data-task',
-      name: 'health-data-task',
-      handler: async () => {
-        try {
-          console.log('后台任务：更新健康数据和检查压力水平...');
-          // 后台任务只更新健康数据，强制刷新以获取最新数据
-          await loadHealthData(undefined, true);
+    // 只有在后台任务管理器初始化完成后才注册任务
+    if (isInitialized) {
+      console.log('后台任务管理器已初始化，开始注册健康数据任务...');
+      registerTask({
+        id: 'health-data-task',
+        name: 'health-data-task',
+        handler: async () => {
+          try {
+            console.log('后台任务：更新健康数据和检查压力水平...');
+            // 后台任务只更新健康数据，强制刷新以获取最新数据
+            await loadHealthData(undefined, true);
 
-          // 执行压力检查
-          await checkStressLevelAndNotify();
+            // 执行压力检查
+            await checkStressLevelAndNotify();
 
-          // 执行喝水目标检查
-          await checkWaterGoalAndNotify();
-        } catch (error) {
-          console.error('健康数据任务执行失败:', error);
-        }
-      },
-    });
-  }, []);
+            // 执行喝水目标检查
+            await checkWaterGoalAndNotify();
+          } catch (error) {
+            console.error('健康数据任务执行失败:', error);
+          }
+        },
+      }).then(() => {
+        console.log('健康数据任务注册成功');
+      }).catch((error) => {
+        console.error('健康数据任务注册失败:', error);
+      });
+    }
+  }, [isInitialized]);
 
   // 检查压力水平并发送通知
   const checkStressLevelAndNotify = React.useCallback(async () => {
@@ -599,16 +606,18 @@ export default function ExploreScreen() {
             </View>
           </View>
 
-          <WeightHistoryCard />
+
 
           {/* 日期选择器 */}
           <DateSelector
             selectedIndex={selectedIndex}
             onDateSelect={onSelectDate}
-            showMonthTitle={true}
+            showMonthTitle={false}
             disableFutureDates={true}
           />
 
+
+
           {/* 营养摄入雷达图卡片 */}
           <NutritionRadarCard
             nutritionSummary={nutritionSummary}
@@ -624,6 +633,8 @@ export default function ExploreScreen() {
             }}
           />
 
+          <WeightHistoryCard />
+
           {/* 真正瀑布流布局 */}
           <View style={styles.masonryContainer}>
             {/* 左列 */}
@@ -768,7 +779,7 @@ const styles = StyleSheet.create({
     paddingHorizontal: 20,
   },
   headerContainer: {
-    marginBottom: 20,
+    marginBottom: 10,
   },
   headerContent: {
     flexDirection: 'row',
@@ -1002,8 +1013,8 @@ const styles = StyleSheet.create({
   masonryContainer: {
     marginBottom: 16,
     flexDirection: 'row',
-    gap: 12,
-    marginTop: 16,
+    gap: 16,
+    marginTop: 6,
   },
   masonryColumn: {
     flex: 1,
@@ -1023,6 +1034,7 @@ const styles = StyleSheet.create({
     elevation: 6,
     minHeight: 100,
     justifyContent: 'center',
+    marginTop: 6
   },
   basalMetabolismCardOverride: {
     margin: -16, // 抵消 masonryCard 的 padding