feat: 更新应用名称和图标，优化用户界面

- 将应用名称修改为“Health Bot”，提升品牌识别度
- 更新应用图标为 logo.png，确保视觉一致性
- 删除不再使用的 ai-coach-chat 页面，简化代码结构
- 更新多个页面的导航和按钮文本，提升用户体验
- 添加体重历史记录功能，支持用户追踪健康数据
- 优化 Redux 状态管理，确保数据处理的准确性和稳定性

app/(tabs)/_layout.tsx

@@ -41,7 +41,7 @@ export default function TabLayout() {
                 case 'index':
                   return { icon: 'house.fill', title: '首页' } as const;
                 case 'coach':
-                  return { icon: 'person.3.fill', title: '教练' } as const;
+                  return { icon: 'person.3.fill', title: 'Bot' } as const;
                 case 'explore':
                   return { icon: 'paperplane.fill', title: '探索' } as const;
                 case 'personal':
@@ -156,7 +156,7 @@ export default function TabLayout() {
       <Tabs.Screen
         name="coach"
         options={{
-          title: '教练',
+          title: 'Bot',
           tabBarIcon: ({ color }) => {
             const isCoachSelected = pathname === '/coach';
             return (
@@ -173,7 +173,7 @@ export default function TabLayout() {
                       textAlign: 'center',
                       flexShrink: 0,
                     }}>
-                    教练
+                    Bot
                   </Text>
                 )}
               </View>

app/(tabs)/explore.tsx

@@ -2,6 +2,7 @@ import { AnimatedNumber } from '@/components/AnimatedNumber';
 import { BMICard } from '@/components/BMICard';
 import { CircularRing } from '@/components/CircularRing';
 import { ProgressBar } from '@/components/ProgressBar';
+import { WeightHistoryCard } from '@/components/WeightHistoryCard';
 import { Colors } from '@/constants/Colors';
 import { getTabBarBottomPadding } from '@/constants/TabBar';
 import { useAppSelector } from '@/hooks/redux';
@@ -137,6 +138,10 @@ export default function ExploreScreen() {
           contentContainerStyle={{ paddingBottom: bottomPadding }}
           showsVerticalScrollIndicator={false}
         >
+                  {/* 体重历史记录卡片 */}
+                  <Text style={styles.sectionTitle}>健康数据</Text>
+          <WeightHistoryCard />
+          
           {/* 标题与日期选择 */}
           <Text style={styles.monthTitle}>{monthTitle}</Text>
           <ScrollView
@@ -224,6 +229,8 @@ export default function ExploreScreen() {
             weight={userProfile?.weight ? parseFloat(userProfile.weight) : undefined}
             height={userProfile?.height ? parseFloat(userProfile.height) : undefined}
           />
+
+  
         </ScrollView>
       </SafeAreaView>
     </View>

app/(tabs)/index.tsx

@@ -8,9 +8,10 @@ import { useAppDispatch, useAppSelector } from '@/hooks/redux';
 import { useColorScheme } from '@/hooks/useColorScheme';
 import { listRecommendedArticles } from '@/services/articles';
 import { fetchRecommendations, RecommendationType } from '@/services/recommendations';
-import { loadPlans, type TrainingPlan } from '@/store/trainingPlanSlice';
+import { loadPlans } from '@/store/trainingPlanSlice';
 // Removed WorkoutCard import since we no longer use the horizontal carousel
 import { useAuthGuard } from '@/hooks/useAuthGuard';
+import { TrainingPlan } from '@/services/trainingPlanApi';
 import { getChineseGreeting } from '@/utils/date';
 import { useRouter } from 'expo-router';
 import React from 'react';
@@ -29,7 +30,7 @@ export default function HomeScreen() {
   const { width: windowWidth, height: windowHeight } = useWindowDimensions();
 
   // 训练计划状态
-  const { plans, currentId } = useAppSelector((s) => s.trainingPlan);
+  const { plans } = useAppSelector((s) => s.trainingPlan);
   const [activePlan, setActivePlan] = React.useState<TrainingPlan | null>(null);
 
   // Draggable coach badge state
@@ -148,13 +149,13 @@ export default function HomeScreen() {
 
   // 获取激活的训练计划
   React.useEffect(() => {
-    if (isLoggedIn && currentId && plans.length > 0) {
-      const currentPlan = plans.find(p => p.id === currentId);
+    if (isLoggedIn && plans.length > 0) {
+      const currentPlan = plans.find(p => p.isActive);
       setActivePlan(currentPlan || null);
     } else {
       setActivePlan(null);
     }
-  }, [isLoggedIn, currentId, plans]);
+  }, [isLoggedIn, plans]);
 
   // 拉取推荐接口（已登录时）
   React.useEffect(() => {

app/_layout.tsx

@@ -86,7 +86,7 @@ export default function RootLayout() {
             <Stack.Screen name="workout" options={{ headerShown: false }} />
             <Stack.Screen name="profile/edit" />
             <Stack.Screen name="profile/goals" options={{ headerShown: false }} />
-            <Stack.Screen name="ai-coach-chat" options={{ headerShown: false }} />
+
             <Stack.Screen name="ai-posture-assessment" />
             <Stack.Screen name="auth/login" options={{ headerShown: false }} />
             <Stack.Screen name="legal/user-agreement" options={{ headerShown: true, title: '用户协议' }} />

app/ai-posture-result.tsx

@@ -153,7 +153,7 @@ export default function AIPostureResultScreen() {
             <Ionicons name="checkmark-circle" size={18} color={theme.onPrimary} />
             <Text style={[styles.primaryBtnText, { color: theme.onPrimary }]}>完成并返回</Text>
           </TouchableOpacity>
-          <TouchableOpacity style={[styles.secondaryBtn, { borderColor: theme.border }]} onPress={() => router.push('/ai-coach-chat')}>
+          <TouchableOpacity style={[styles.secondaryBtn, { borderColor: theme.border }]} onPress={() => router.push('/(tabs)/coach')}>
             <Text style={[styles.secondaryBtnText, { color: theme.text }]}>生成训练建议</Text>
           </TouchableOpacity>
         </View>