feat: 扩展前端WebSocket与导航

- 优化WebSocketClient、WebSocketMessage
- 更新AppNavigation、MainActivity

Co-authored-by: Cursor <cursoragent@cursor.com>

app-android/app/src/main/java/com/huaga/life_echo/MainActivity.kt

@@ -25,7 +25,6 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.statusBars
 import androidx.compose.foundation.layout.windowInsetsPadding
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.ui.draw.scale
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Scaffold
@@ -39,18 +38,18 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.scale
 import androidx.compose.ui.graphics.vector.ImageVector
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.font.FontWeight
-import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.tooling.preview.PreviewScreenSizes
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.core.view.WindowCompat
-import androidx.core.view.WindowInsetsControllerCompat
 import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.WindowInsetsControllerCompat
 import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.compose.rememberNavController
-import androidx.compose.ui.platform.LocalContext
 import com.huaga.life_echo.data.auth.TokenManager
 import com.huaga.life_echo.navigation.AppNavigation
 import com.huaga.life_echo.navigation.Screen

app-android/app/src/main/java/com/huaga/life_echo/navigation/AppNavigation.kt

@@ -25,6 +25,7 @@ sealed class Screen(val route: String) {
     object MyOrders : Screen("my_orders")
     object ExportData : Screen("export_data")
     object PlanDetails : Screen("plan_details")
+    object PlanBalance : Screen("plan_balance")  // 套餐余额
     object FAQ : Screen("faq")
     object Feedback : Screen("feedback")
     object About : Screen("about")
@@ -134,6 +135,15 @@ fun AppNavigation(
         ) {
             PlanDetailsScreen(navController = navController)
         }
+        composable(
+            route = Screen.PlanBalance.route,
+            enterTransition = { slideInHorizontally() },
+            exitTransition = { slideOutHorizontally() },
+            popEnterTransition = { slideInHorizontallyFromLeft() },
+            popExitTransition = { slideOutHorizontallyToRight() }
+        ) {
+            PlanBalanceScreen(navController = navController)
+        }
         composable(
             route = Screen.FAQ.route,
             enterTransition = { slideInHorizontally() },

app-android/app/src/main/java/com/huaga/life_echo/network/WebSocketClient.kt

@@ -234,6 +234,20 @@ class WebSocketClient {
         ))
     }
     
+    /**
+     * 仅转写：发送音频获取文字，不落库、不触发 Agent，用于「转文字」后客户端再发文本
+     */
+    suspend fun sendTranscribeOnly(audioBytes: ByteArray, conversationId: String) {
+        Log.d(TAG, "发送仅转写请求，大小: ${audioBytes.size} 字节")
+        if (!isConnected) throw Exception("WebSocket未连接，请先建立连接")
+        val base64Audio = android.util.Base64.encodeToString(audioBytes, android.util.Base64.NO_WRAP)
+        sendMessage(WebSocketMessage(
+            type = MessageType.transcribe_only,
+            conversation_id = conversationId,
+            data = buildJsonObject { put("audio_base64", JsonPrimitive(base64Audio)) }
+        ))
+    }
+    
     suspend fun sendTextMessage(text: String, conversationId: String) {
         Log.d(TAG, "准备发送文本消息: $text")
         if (!isConnected) {

app-android/app/src/main/java/com/huaga/life_echo/network/WebSocketMessage.kt

@@ -10,6 +10,7 @@ enum class MessageType {
     connect,
     audio_chunk,
     audio_message,        // 完整音频消息（类似微信语音）
+    transcribe_only,      // 仅转写，不落库不触发 Agent，用于「转文字」发送
     text,  // 文本消息
     transcript,           // 语音转文字结果
     agent_response,