fix(audio): 修复蓝牙音频路由问题并优化外部音频源处理

强制禁用HFP通话音道，改为使用手机麦克风加A2DP输出
新增耳机/蓝牙输出设备检测功能
优化外部音频源的会话配置逻辑

local_plugins/azure_speech/ios/azure_speech/Sources/tools/SimpleAudioReceiver.swift

@@ -123,6 +123,9 @@ public class SimpleAudioReceiver: NSObject {
     
     /**
      * 开始音频输入
+     * 参数：audioSourceType 音频源类型（microphone 或 external）；audioDataCallback 音频数据回调
+     * 返回值：无
+     * 异常：无（内部捕获并打印错误，不抛出）
      */
     public func startAudioRecord(audioSourceType: AudioSourceType = .microphone, audioDataCallback: AudioDataCallback?) {
         _isWriting=true
@@ -131,8 +134,10 @@ public class SimpleAudioReceiver: NSObject {
             print("音源设制---------- startAudioRecord=audioSourceType:\(audioSourceType)") 
             switch audioSourceType {
             case .microphone:
-                // 根据当前可用输入设备动态判定是否存在蓝牙HFP麦克风
+                // 唤醒后禁用通话音道（HFP），改为手机麦克风 + A2DP 输出
-                isReceiverHFP = hasBluetoothHFPInput()
+                isReceiverHFP = false
+                // 动态检测是否存在耳机/蓝牙输出，用于后续路由选项计算
+                isHeadphones = detectHeadphonesOutput()
                 runMicrophoneCapture()
             case .external:
                 isReceiverHFP = false
@@ -155,6 +160,23 @@ public class SimpleAudioReceiver: NSObject {
         return session.currentRoute.inputs.contains { $0.portType == .bluetoothHFP }
     }
     
+    /**
+     * 检测是否存在耳机/蓝牙输出设备（用于决定是否启用A2DP而非扬声器）
+     * 参数：无
+     * 返回值：存在返回true，否则返回false
+     * 异常：无
+     */
+    private func detectHeadphonesOutput() -> Bool {
+        let session = AVAudioSession.sharedInstance()
+        let outputs = session.currentRoute.outputs
+        return outputs.contains { out in
+            out.portType == .bluetoothA2DP ||
+            out.portType == .bluetoothHFP ||
+            out.portType == .bluetoothLE ||
+            out.portType == .headphones
+        }
+    }
+    
     /**
      * 开启音频写入线程
      * 修复：使用userInitiated QoS避免优先级反转
@@ -246,13 +268,50 @@ public class SimpleAudioReceiver: NSObject {
     private func runExternalCapture() {
         if audioSourceType == .external {
             do {
-                 // 根据通话状态进行安全的音频会话配置
+                 // 停止麦克风采集，确保不走通话音道
-                 try safeConfigureAudioSessionForMic()
+                 micCapture.stopCapture()
+                 // 外部模式会话配置：禁止HFP，仅允许A2DP/耳机输出
+                 try safeConfigureAudioSessionForExternal()
             } catch {
                 print("设置音频会话失败: \(error.localizedDescription)")
             }
             //pushAudioData(data: Data())
-            micCapture.stopCapture()
+        }
+    }
+    
+    /**
+     * 外部音频源的安全音频会话配置（禁止HFP通话音道）
+     * 参数：无
+     * 返回值：无
+     * 异常：可能抛出AVAudioSession设置错误（内部捕获并兜底）
+     */
+    private func safeConfigureAudioSessionForExternal() throws {
+        let audioSession = self.audioSession
+        do {
+            // 外部模式不录麦，仅做播放路由；有耳机时只允许A2DP，禁止HFP
+            let outputs = audioSession.currentRoute.outputs
+            let hasHeadphones = outputs.contains { out in
+                out.portType == .bluetoothA2DP ||
+                out.portType == .bluetoothLE ||
+                out.portType == .headphones
+            }
+            let desiredCategory: AVAudioSession.Category = .playback
+            let desiredMode: AVAudioSession.Mode = .videoChat
+            let desiredOptions: AVAudioSession.CategoryOptions = hasHeadphones
+                ? [.allowBluetoothA2DP, .mixWithOthers]
+                : [.mixWithOthers, .defaultToSpeaker]
+            
+            let needsSetCategory = (audioSession.category != desiredCategory) || (audioSession.mode != desiredMode)
+            if needsSetCategory {
+                try audioSession.setCategory(desiredCategory, mode: desiredMode, options: desiredOptions)
+            }
+            // 取消扬声器强制，确保耳机/A2DP优先
+            try audioSession.overrideOutputAudioPort(.none)
+            try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
+        } catch {
+            print("外部模式音频会话配置失败，兜底到playback: \(error)")
+            try audioSession.setCategory(.playback, mode: .default, options: [.mixWithOthers, .defaultToSpeaker])
+            try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
         }
     }
     /**
@@ -592,4 +651,3 @@ private class LinkedBlockingQueue<T> {
         }
     }
 }
-