feat: 添加教练功能和更新用户界面

- 新增教练页面，用户可以与教练进行互动和咨询
- 更新首页，切换到教练 tab 并传递名称参数
- 优化个人信息页面，添加注销帐号和退出登录功能
- 更新隐私政策和用户协议的链接，确保用户在使用前同意相关条款
- 修改今日训练页面标题为“开始训练”，提升用户体验
- 删除不再使用的进度条组件，简化代码结构

app/(tabs)/index.tsx

@@ -75,9 +75,8 @@ export default function HomeScreen() {
       const snapX = distLeft <= distRight ? minX : maxX;
       Animated.spring(pan, { toValue: { x: snapX, y: clampedY }, useNativeDriver: false, bounciness: 6 }).start(() => {
         if (!dragState.current.moved) {
-          // Treat as tap
-          // @ts-ignore - expo-router string ok
-          router.push('/ai-coach-chat?name=Iris' as any);
+          // 切换到教练 tab，并传递name参数
+          router.push('/coach?name=Iris' as any);
         }
       });
     },
@@ -91,7 +90,6 @@ export default function HomeScreen() {
       title: string;
       subtitle: string;
       level?: '初学者' | '中级' | '高级';
-      progress: number;
       onPress?: () => void;
     }
     | {
@@ -115,7 +113,6 @@ export default function HomeScreen() {
         title: '今日训练',
         subtitle: '完成一次普拉提训练，记录你的坚持',
         level: '初学者',
-        progress: 0,
         onPress: () => pushIfAuthedElseLogin('/workout/today'),
       },
       {
@@ -126,7 +123,6 @@ export default function HomeScreen() {
         title: '体态评估',
         subtitle: '评估你的体态，制定训练计划',
         level: '初学者',
-        progress: 0,
         onPress: () => router.push('/ai-posture-assessment'),
       },
       ...listRecommendedArticles().map((a) => ({
@@ -194,7 +190,6 @@ export default function HomeScreen() {
               image: 'https://plates-1251306435.cos.ap-guangzhou.myqcloud.com/images/imagedemo.jpeg',
               title: c.title || '今日训练',
               subtitle: c.subtitle || '完成一次普拉提训练，记录你的坚持',
-              progress: 0,
               onPress: () => pushIfAuthedElseLogin('/workout/today'),
             });
           }
@@ -282,6 +277,22 @@ export default function HomeScreen() {
             <ThemedText style={styles.sectionTitle}>热点功能</ThemedText>
 
             <View style={styles.featureGrid}>
+
+            <Pressable
+                style={[styles.featureCard, styles.featureCardQuinary]}
+                onPress={() => pushIfAuthedElseLogin('/workout/today')}
+              >
+                <View style={styles.featureIconWrapper}>
+                  <View style={styles.featureIconPlaceholder}>
+                  <Image
+                    source={require('@/assets/images/icons/iconWorkout.png')}
+                    style={styles.featureIconImage}
+                  />
+                  </View>
+                </View>
+                <ThemedText style={styles.featureTitle}>训练</ThemedText>
+              </Pressable>
+
               <Pressable
                 style={[styles.featureCard, styles.featureCardPrimary]}
                 onPress={() => router.push('/ai-posture-assessment')}
@@ -292,7 +303,7 @@ export default function HomeScreen() {
                     style={styles.featureIconImage}
                   />
                 </View>
-                <ThemedText style={styles.featureTitle}>AI体态评估</ThemedText>
+                <ThemedText style={styles.featureTitle}>体态</ThemedText>
               </Pressable>
 
               <Pressable
@@ -307,8 +318,11 @@ export default function HomeScreen() {
                   />
                   </View>
                 </View>
-                <ThemedText style={styles.featureTitle}>计划管理</ThemedText>
+                <ThemedText style={styles.featureTitle}>计划</ThemedText>
               </Pressable>
+
+
+       
             </View>
           </View>
 
@@ -344,7 +358,6 @@ export default function HomeScreen() {
                     title={item.title}
                     subtitle={item.subtitle}
                     level={item.level}
-                    progress={item.progress}
                   />
                 );
                 return item.onPress ? (
@@ -490,6 +503,9 @@ const styles = StyleSheet.create({
   featureCardQuaternary: {
     backgroundColor: '#fa709a',
   },
+  featureCardQuinary: {
+    backgroundColor: '#f59e0b',
+  },
   featureIconWrapper: {
     width: 32,
     height: 32,