feat: 新增前端支付模块

- 新增payment/支付管理（PaymentManager、微信/支付宝Handler）
- 新增wxapi/WXPayEntryActivity微信支付回调
- 扩展ApiService、PaymentModels、PaymentRepository

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

app-android/app/src/main/java/com/huaga/life_echo/data/repository/PaymentRepository.kt

@@ -1,9 +1,12 @@
 package com.huaga.life_echo.data.repository
 
 import com.huaga.life_echo.network.ApiService
+import com.huaga.life_echo.network.models.CreatePaymentOrderResponse
 import com.huaga.life_echo.network.models.OrderDto
+import com.huaga.life_echo.network.models.PaymentOrderStatusResponse
 import com.huaga.life_echo.network.models.PlanDto
 import com.huaga.life_echo.network.models.QuotaCheckDto
+import com.huaga.life_echo.network.models.TestSubscriptionResponse
 
 class PaymentRepository(
     private val apiService: ApiService
@@ -31,4 +34,37 @@ class PaymentRepository(
     suspend fun getOrderById(orderId: String): Result<OrderDto> {
         return apiService.getOrderById(orderId)
     }
+    
+    // ==================== 支付订单（微信/支付宝） ====================
+    
+    /**
+     * 创建支付订单（获取支付参数）
+     */
+    suspend fun createPaymentOrder(
+        planId: String,
+        paymentMethod: String
+    ): Result<CreatePaymentOrderResponse> {
+        return apiService.createPaymentOrder(planId, paymentMethod)
+    }
+    
+    /**
+     * 查询支付订单状态
+     */
+    suspend fun getPaymentOrderStatus(orderId: String): Result<PaymentOrderStatusResponse> {
+        return apiService.getPaymentOrderStatus(orderId)
+    }
+    
+    /**
+     * 获取支付订单列表
+     */
+    suspend fun getPaymentOrders(): Result<List<PaymentOrderStatusResponse>> {
+        return apiService.getPaymentOrders()
+    }
+
+    /**
+     * 测试订阅开关（仅当服务端开启时可用）
+     */
+    suspend fun setTestSubscription(action: String, planId: String = "pro"): Result<TestSubscriptionResponse> {
+        return apiService.setTestSubscription(action, planId)
+    }
 }

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

@@ -237,7 +237,75 @@ class ApiService(
         }
     }
     
+    // ==================== 支付订单API（微信/支付宝） ====================
+    
+    /**
+     * 创建支付订单
+     * 返回微信支付参数或支付宝订单字符串
+     */
+    suspend fun createPaymentOrder(
+        planId: String,
+        paymentMethod: String
+    ): Result<CreatePaymentOrderResponse> {
+        return try {
+            val response = client.post("$BASE_URL/api/payment/create-order") {
+                contentType(ContentType.Application.Json)
+                setBody(CreatePaymentOrderRequest(planId, paymentMethod))
+            }
+            Result.success(response.body())
+        } catch (e: Exception) {
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 查询支付订单状态
+     */
+    suspend fun getPaymentOrderStatus(orderId: String): Result<PaymentOrderStatusResponse> {
+        return try {
+            val response = client.get("$BASE_URL/api/payment/order/$orderId/status") {
+                contentType(ContentType.Application.Json)
+            }
+            Result.success(response.body())
+        } catch (e: Exception) {
+            Result.failure(e)
+        }
+    }
+    
+    /**
+     * 获取支付订单列表（新接口）
+     */
+    suspend fun getPaymentOrders(): Result<List<PaymentOrderStatusResponse>> {
+        return try {
+            val response = client.get("$BASE_URL/api/payment/orders") {
+                contentType(ContentType.Application.Json)
+            }
+            Result.success(response.body())
+        } catch (e: Exception) {
+            Result.failure(e)
+        }
+    }
+    
     // ==================== 用户相关API ====================
+
+    /**
+     * 测试订阅开关（仅当服务端 ENABLE_TEST_SUBSCRIPTION=1 时可用）
+     * 用于微信支付审核通过前模拟付费通过，体验订阅额度。
+     */
+    suspend fun setTestSubscription(
+        action: String,
+        planId: String = "pro"
+    ): Result<TestSubscriptionResponse> {
+        return try {
+            val response = client.post("$BASE_URL/api/user/test-subscription") {
+                contentType(ContentType.Application.Json)
+                setBody(TestSubscriptionRequest(action = action, planId = planId))
+            }
+            Result.success(response.body())
+        } catch (e: Exception) {
+            Result.failure(e)
+        }
+    }
     
     suspend fun getUserProfile(): Result<UserProfileDto> {
         return try {

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

@@ -1,5 +1,6 @@
 package com.huaga.life_echo.network.models
 
+import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
 /**
@@ -18,19 +19,22 @@ data class PlanBenefitDto(
     val features: List<String> = emptyList() // 功能列表
 )
 
-// 套餐信息DTO
+// 套餐信息DTO（与后端 /api/plans 返回字段对应）
 @Serializable
 data class PlanDto(
     val id: String,
     val name: String,
-    val displayName: String,
+    @SerialName("display_name") val displayName: String,
     val price: Double,
     val currency: String = "CNY",
-    val billingCycle: String, // "monthly", "yearly"
+    @SerialName("billing_cycle") val billingCycle: String? = null,
     val benefits: List<PlanBenefitDto> = emptyList(),
     val features: List<String> = emptyList(),
     val isActive: Boolean = true,
-    val isCurrentPlan: Boolean = false
+    val isCurrentPlan: Boolean = false,
+    @SerialName("max_conversations") val maxConversations: Int? = null,
+    @SerialName("max_chapters") val maxChapters: Int? = null,
+    @SerialName("is_popular") val isPopular: Boolean = false
 )
 
 // 订单信息DTO
@@ -69,5 +73,84 @@ data class QuotaCheckDto(
     val remainingWords: Int? = null,
     val remainingChapters: Int? = null,
     val remainingConversations: Int? = null,
+    // 已用量与上限（用于展示 "已用 X / 共 Y"）
+    val usedConversations: Int? = null,
+    val usedChapters: Int? = null,
+    val maxConversations: Int? = null,
+    val maxChapters: Int? = null,
     val message: String? = null
 )
+
+// ==================== 支付订单相关模型 ====================
+
+/**
+ * 创建支付订单请求
+ */
+@Serializable
+data class CreatePaymentOrderRequest(
+    @SerialName("plan_id") val planId: String,
+    @SerialName("payment_method") val paymentMethod: String // "wechat" / "alipay"
+)
+
+/**
+ * 创建支付订单响应
+ */
+@Serializable
+data class CreatePaymentOrderResponse(
+    @SerialName("order_id") val orderId: String,
+    @SerialName("payment_method") val paymentMethod: String,
+    // 微信支付参数（仅当 paymentMethod == "wechat" 时有值）
+    @SerialName("wechat_params") val wechatParams: WeChatPayParamsDto? = null,
+    // 支付宝订单字符串（仅当 paymentMethod == "alipay" 时有值）
+    @SerialName("alipay_order_string") val alipayOrderString: String? = null
+)
+
+/**
+ * 微信支付参数 DTO
+ */
+@Serializable
+data class WeChatPayParamsDto(
+    val appId: String = "",
+    val partnerId: String = "",
+    val prepayId: String = "",
+    val nonceStr: String = "",
+    val timeStamp: String = "",
+    val sign: String = "",
+    val packageValue: String = "Sign=WXPay"
+)
+
+/**
+ * 订单状态查询响应
+ */
+@Serializable
+data class PaymentOrderStatusResponse(
+    @SerialName("order_id") val orderId: String,
+    @SerialName("plan_id") val planId: String,
+    @SerialName("plan_name") val planName: String,
+    val amount: Int,           // 金额（分）
+    val currency: String,
+    @SerialName("payment_method") val paymentMethod: String,
+    val status: String,        // pending / paid / failed / cancelled / refunded
+    @SerialName("trade_no") val tradeNo: String? = null,
+    @SerialName("created_at") val createdAt: String,
+    @SerialName("paid_at") val paidAt: String? = null
+)
+
+/**
+ * 测试订阅请求（仅开发/测试环境，微信支付审核通过前使用）
+ */
+@Serializable
+data class TestSubscriptionRequest(
+    val action: String,  // "activate" | "deactivate"
+    @SerialName("plan_id") val planId: String? = "pro"
+)
+
+/**
+ * 测试订阅响应
+ */
+@Serializable
+data class TestSubscriptionResponse(
+    val success: Boolean,
+    val message: String,
+    @SerialName("subscription_type") val subscriptionType: String
+)

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

@@ -0,0 +1,106 @@
+package com.huaga.life_echo.payment
+
+import android.app.Activity
+import android.util.Log
+import com.alipay.sdk.app.PayTask
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+/**
+ * 支付宝支付处理器
+ *
+ * 负责：
+ * 1. 调起支付宝 APP 支付
+ * 2. 解析支付结果
+ */
+class AlipayHandler {
+
+    companion object {
+        private const val TAG = "AlipayHandler"
+    }
+
+    /**
+     * 发起支付宝支付
+     *
+     * 注意：此方法需要在协程中调用（内部会切换到 IO 线程）
+     *
+     * @param activity 当前 Activity
+     * @param orderString 从服务端获取的支付宝订单字符串
+     * @param orderId 内部订单号
+     * @return PaymentResult
+     */
+    suspend fun startPay(
+        activity: Activity,
+        orderString: String,
+        orderId: String
+    ): PaymentResult = withContext(Dispatchers.IO) {
+        try {
+            Log.d(TAG, "发起支付宝支付: orderId=$orderId")
+
+            val payTask = PayTask(activity)
+            val result: Map<String, String> = payTask.payV2(orderString, true)
+
+            Log.d(TAG, "支付宝支付结果: $result")
+
+            parseResult(result, orderId)
+        } catch (e: Exception) {
+            Log.e(TAG, "支付宝支付异常", e)
+            PaymentResult.Failure(
+                orderId = orderId,
+                paymentMethod = "alipay",
+                errorCode = -1,
+                errorMessage = e.message ?: "支付异常"
+            )
+        }
+    }
+
+    /**
+     * 解析支付宝支付结果
+     */
+    private fun parseResult(result: Map<String, String>, orderId: String): PaymentResult {
+        val resultStatus = result["resultStatus"] ?: ""
+        val memo = result["memo"] ?: ""
+
+        return when (resultStatus) {
+            "9000" -> {
+                // 支付成功
+                Log.d(TAG, "支付宝支付成功: orderId=$orderId")
+                PaymentResult.Success(orderId = orderId, paymentMethod = "alipay")
+            }
+            "6001" -> {
+                // 用户取消
+                Log.d(TAG, "支付宝支付取消: orderId=$orderId")
+                PaymentResult.Cancelled(orderId = orderId, paymentMethod = "alipay")
+            }
+            "6002" -> {
+                // 网络连接出错
+                Log.e(TAG, "支付宝支付网络错误: orderId=$orderId")
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "alipay",
+                    errorCode = 6002,
+                    errorMessage = "网络连接异常，请检查网络后重试"
+                )
+            }
+            "4000" -> {
+                // 支付失败
+                Log.e(TAG, "支付宝支付失败: orderId=$orderId, memo=$memo")
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "alipay",
+                    errorCode = 4000,
+                    errorMessage = memo.ifEmpty { "支付失败" }
+                )
+            }
+            else -> {
+                Log.e(TAG, "支付宝支付未知状态: resultStatus=$resultStatus, memo=$memo")
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "alipay",
+                    errorCode = resultStatus.toIntOrNull() ?: -1,
+                    errorMessage = memo.ifEmpty { "支付异常($resultStatus)" }
+                )
+            }
+        }
+    }
+}

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

@@ -0,0 +1,82 @@
+package com.huaga.life_echo.payment
+
+import android.app.Activity
+import android.content.Context
+import android.util.Log
+
+/**
+ * 统一支付管理器
+ *
+ * 提供统一的支付入口，屏蔽微信/支付宝底层差异
+ *
+ * 使用方式：
+ * ```
+ * val manager = PaymentManager(context, wechatAppId)
+ *
+ * // 微信支付
+ * manager.startWeChatPay(activity, params, orderId) { result -> ... }
+ *
+ * // 支付宝支付
+ * val result = manager.startAlipay(activity, orderString, orderId)
+ * ```
+ */
+class PaymentManager(
+    context: Context,
+    wechatAppId: String
+) {
+    companion object {
+        private const val TAG = "PaymentManager"
+    }
+
+    private val weChatPayHandler = WeChatPayHandler(context.applicationContext, wechatAppId)
+    private val alipayHandler = AlipayHandler()
+
+    /**
+     * 检查微信是否已安装
+     */
+    fun isWeChatInstalled(): Boolean {
+        return weChatPayHandler.isWeChatInstalled()
+    }
+
+    /**
+     * 发起微信支付
+     *
+     * @param params 从服务端获取的微信支付参数
+     * @param orderId 内部订单号
+     * @param callback 支付结果回调（在主线程）
+     */
+    fun startWeChatPay(
+        params: WeChatPayParams,
+        orderId: String,
+        callback: (PaymentResult) -> Unit
+    ) {
+        Log.d(TAG, "发起微信支付: orderId=$orderId")
+        weChatPayHandler.startPay(params, orderId, callback)
+    }
+
+    /**
+     * 发起支付宝支付
+     *
+     * 注意：此方法需要在协程中调用
+     *
+     * @param activity 当前 Activity
+     * @param orderString 从服务端获取的支付宝订单字符串
+     * @param orderId 内部订单号
+     * @return PaymentResult
+     */
+    suspend fun startAlipay(
+        activity: Activity,
+        orderString: String,
+        orderId: String
+    ): PaymentResult {
+        Log.d(TAG, "发起支付宝支付: orderId=$orderId")
+        return alipayHandler.startPay(activity, orderString, orderId)
+    }
+
+    /**
+     * 释放资源，在不需要时调用
+     */
+    fun release() {
+        weChatPayHandler.release()
+    }
+}

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

@@ -0,0 +1,39 @@
+package com.huaga.life_echo.payment
+
+/**
+ * 支付结果封装
+ */
+sealed class PaymentResult {
+    /** 支付成功 */
+    data class Success(
+        val orderId: String,
+        val paymentMethod: String
+    ) : PaymentResult()
+
+    /** 支付失败 */
+    data class Failure(
+        val orderId: String,
+        val paymentMethod: String,
+        val errorCode: Int = -1,
+        val errorMessage: String = "支付失败"
+    ) : PaymentResult()
+
+    /** 用户取消支付 */
+    data class Cancelled(
+        val orderId: String,
+        val paymentMethod: String
+    ) : PaymentResult()
+}
+
+/**
+ * 微信支付调起参数（从服务端获取）
+ */
+data class WeChatPayParams(
+    val appId: String,
+    val partnerId: String,
+    val prepayId: String,
+    val nonceStr: String,
+    val timeStamp: String,
+    val sign: String,
+    val packageValue: String = "Sign=WXPay"
+)

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

@@ -0,0 +1,187 @@
+package com.huaga.life_echo.payment
+
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.util.Log
+import com.tencent.mm.opensdk.modelpay.PayReq
+import com.tencent.mm.opensdk.openapi.IWXAPI
+import com.tencent.mm.opensdk.openapi.WXAPIFactory
+
+/**
+ * 微信支付处理器
+ *
+ * 负责：
+ * 1. 注册微信 SDK
+ * 2. 调起微信支付
+ * 3. 接收支付结果（通过 WXPayEntryActivity 转发）
+ */
+class WeChatPayHandler(
+    private val context: Context,
+    private val appId: String
+) {
+    companion object {
+        private const val TAG = "WeChatPayHandler"
+
+        /** 微信支付结果广播 Action */
+        const val ACTION_WECHAT_PAY_RESULT = "com.huaga.life_echo.WECHAT_PAY_RESULT"
+        const val EXTRA_ERROR_CODE = "error_code"
+        const val EXTRA_ERROR_MSG = "error_msg"
+    }
+
+    private val wxApi: IWXAPI by lazy {
+        WXAPIFactory.createWXAPI(context, appId, true).also {
+            it.registerApp(appId)
+        }
+    }
+
+    /** 当前等待支付结果的回调 */
+    private var pendingCallback: ((PaymentResult) -> Unit)? = null
+    private var pendingOrderId: String? = null
+
+    /** 广播接收器：接收来自 WXPayEntryActivity 的支付结果 */
+    private val payResultReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context?, intent: Intent?) {
+            val errCode = intent?.getIntExtra(EXTRA_ERROR_CODE, -1) ?: -1
+            val errMsg = intent?.getStringExtra(EXTRA_ERROR_MSG) ?: ""
+            handlePayResult(errCode, errMsg)
+        }
+    }
+
+    private var isReceiverRegistered = false
+
+    /**
+     * 检查微信是否已安装
+     */
+    fun isWeChatInstalled(): Boolean {
+        return wxApi.isWXAppInstalled
+    }
+
+    /**
+     * 发起微信支付
+     *
+     * @param params 从服务端获取的支付参数
+     * @param orderId 内部订单号
+     * @param callback 支付结果回调
+     */
+    fun startPay(
+        params: WeChatPayParams,
+        orderId: String,
+        callback: (PaymentResult) -> Unit
+    ) {
+        if (!isWeChatInstalled()) {
+            callback(
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "wechat",
+                    errorCode = -2,
+                    errorMessage = "未安装微信客户端"
+                )
+            )
+            return
+        }
+
+        // 保存回调
+        pendingCallback = callback
+        pendingOrderId = orderId
+
+        // 注册广播接收器
+        registerReceiver()
+
+        // 构建支付请求
+        val req = PayReq().apply {
+            appId = params.appId
+            partnerId = params.partnerId
+            prepayId = params.prepayId
+            nonceStr = params.nonceStr
+            timeStamp = params.timeStamp
+            sign = params.sign
+            packageValue = params.packageValue
+        }
+
+        Log.d(TAG, "发起微信支付: orderId=$orderId")
+        val result = wxApi.sendReq(req)
+        if (!result) {
+            Log.e(TAG, "微信支付调起失败")
+            pendingCallback?.invoke(
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "wechat",
+                    errorCode = -3,
+                    errorMessage = "微信支付调起失败"
+                )
+            )
+            pendingCallback = null
+            pendingOrderId = null
+        }
+    }
+
+    /**
+     * 处理微信支付结果
+     * 由广播接收器调用
+     */
+    private fun handlePayResult(errCode: Int, errMsg: String) {
+        val orderId = pendingOrderId ?: ""
+        val callback = pendingCallback
+
+        // 清理状态
+        pendingCallback = null
+        pendingOrderId = null
+
+        val result = when (errCode) {
+            0 -> {
+                Log.d(TAG, "微信支付成功: orderId=$orderId")
+                PaymentResult.Success(orderId = orderId, paymentMethod = "wechat")
+            }
+            -1 -> {
+                Log.e(TAG, "微信支付失败: errCode=$errCode, errMsg=$errMsg")
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "wechat",
+                    errorCode = errCode,
+                    errorMessage = errMsg.ifEmpty { "支付失败" }
+                )
+            }
+            -2 -> {
+                Log.d(TAG, "微信支付取消: orderId=$orderId")
+                PaymentResult.Cancelled(orderId = orderId, paymentMethod = "wechat")
+            }
+            else -> {
+                Log.e(TAG, "微信支付未知错误: errCode=$errCode")
+                PaymentResult.Failure(
+                    orderId = orderId,
+                    paymentMethod = "wechat",
+                    errorCode = errCode,
+                    errorMessage = "未知错误($errCode)"
+                )
+            }
+        }
+
+        callback?.invoke(result)
+    }
+
+    private fun registerReceiver() {
+        if (!isReceiverRegistered) {
+            val filter = IntentFilter(ACTION_WECHAT_PAY_RESULT)
+            context.registerReceiver(payResultReceiver, filter, Context.RECEIVER_NOT_EXPORTED)
+            isReceiverRegistered = true
+        }
+    }
+
+    /**
+     * 释放资源
+     */
+    fun release() {
+        if (isReceiverRegistered) {
+            try {
+                context.unregisterReceiver(payResultReceiver)
+            } catch (_: Exception) {
+            }
+            isReceiverRegistered = false
+        }
+        pendingCallback = null
+        pendingOrderId = null
+        wxApi.detach()
+    }
+}

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

@@ -0,0 +1,74 @@
+package com.huaga.life_echo.wxapi
+
+import android.app.Activity
+import android.content.Intent
+import android.os.Bundle
+import android.util.Log
+import com.huaga.life_echo.payment.WeChatPayHandler
+import com.tencent.mm.opensdk.constants.ConstantsAPI
+import com.tencent.mm.opensdk.modelbase.BaseReq
+import com.tencent.mm.opensdk.modelbase.BaseResp
+import com.tencent.mm.opensdk.openapi.IWXAPI
+import com.tencent.mm.opensdk.openapi.IWXAPIEventHandler
+import com.tencent.mm.opensdk.openapi.WXAPIFactory
+import com.huaga.life_echo.config.AppConfig
+
+/**
+ * 微信支付结果回调 Activity
+ *
+ * 重要说明：
+ * - 此类必须位于 {应用包名}.wxapi 目录下
+ * - 类名必须为 WXPayEntryActivity
+ * - 这是微信 SDK 的硬性要求，不可更改路径和类名
+ *
+ * 收到微信支付结果后，通过广播转发给 WeChatPayHandler
+ */
+class WXPayEntryActivity : Activity(), IWXAPIEventHandler {
+
+    companion object {
+        private const val TAG = "WXPayEntryActivity"
+    }
+
+    private lateinit var wxApi: IWXAPI
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        wxApi = WXAPIFactory.createWXAPI(this, AppConfig.WECHAT_APP_ID)
+        wxApi.handleIntent(intent, this)
+    }
+
+    override fun onNewIntent(intent: Intent) {
+        super.onNewIntent(intent)
+        setIntent(intent)
+        wxApi.handleIntent(intent, this)
+    }
+
+    /**
+     * 微信发送请求到第三方应用时回调（支付场景不会触发）
+     */
+    override fun onReq(req: BaseReq?) {
+        Log.d(TAG, "onReq: ${req?.type}")
+    }
+
+    /**
+     * 第三方应用发送到微信的请求处理后的响应结果回调
+     * 支付结果在这里接收
+     */
+    override fun onResp(resp: BaseResp?) {
+        Log.d(TAG, "onResp: type=${resp?.type}, errCode=${resp?.errCode}, errStr=${resp?.errStr}")
+
+        if (resp?.type == ConstantsAPI.COMMAND_PAY_BY_WX) {
+            // 通过广播将结果转发给 WeChatPayHandler
+            val intent = Intent(WeChatPayHandler.ACTION_WECHAT_PAY_RESULT).apply {
+                setPackage(packageName)
+                putExtra(WeChatPayHandler.EXTRA_ERROR_CODE, resp.errCode)
+                putExtra(WeChatPayHandler.EXTRA_ERROR_MSG, resp.errStr ?: "")
+            }
+            sendBroadcast(intent)
+        }
+
+        // 关闭此透明 Activity
+        finish()
+    }
+}