feat(导航): 增加接待任务中机器人朝向保持功能

在接待任务中，机器人到达接待位置并检测到人时记录当前朝向作为锚点角度。
当检测状态变为空闲时，自动恢复记录的朝向，避免机器人因微小移动而偏离接待方向。
同时添加角度归一化函数处理角度计算，并确保仅在接待任务相关场景触发此功能。

app/src/main/java/com/example/lzwcai_terminal_temi/MainActivity.kt

@@ -97,6 +97,8 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
     private var blinkJob: Job? = null
     private var networkErrorJob: Job? = null
     private var autoRechargeJob: Job? = null
+    private var latestYaw: Float? = null
+    private var receptionAnchorYaw: Float? = null
     private lateinit var telemetryManager: TelemetryManager
     private lateinit var taskController: TaskController
 
@@ -322,6 +324,7 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
     }
 
     override fun onCurrentPositionChanged(position: Position) {
+        latestYaw = position.yaw
         telemetryManager.onCurrentPositionChanged(position)
     }
 
@@ -355,6 +358,14 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
         if (taskController.currentTask == "patrol") {
             taskController.handlePatrolArrival(location)
         }
+        if (taskController.currentTask == "reception" &&
+            location.equals(taskController.getReceptionLocation(), ignoreCase = true)
+        ) {
+            captureReceptionAnchorYawIfNeeded()
+        }
+        if (taskController.currentTask != "reception") {
+            receptionAnchorYaw = null
+        }
         if (taskController.handleNotificationArrival(location)) {
             return
         }
@@ -406,6 +417,13 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
     private fun handleStableDetectionStateChanged(state: Int) {
         Log.i("MainActivity", "Stable detection state: $state")
         liveKitManager?.setDetectionActive(state == DETECTED)
+        if (taskController.currentTask == "reception") {
+            if (state == DETECTED) {
+                captureReceptionAnchorYawIfNeeded()
+            } else if (state == IDLE) {
+                recoverReceptionFacingDirection()
+            }
+        }
         if (taskController.handleDetectionStateChanged(state)) {
             Log.i("MainActivity", "what the f**k")
             return
@@ -490,6 +508,9 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
         if (task.trim().isNotEmpty()) {
             cancelAutoRecharge("task_set:$task")
         }
+        if (!task.equals("reception", ignoreCase = true)) {
+            receptionAnchorYaw = null
+        }
         taskController.setCurrentTask(task)
     }
 
@@ -762,6 +783,48 @@ class MainActivity : AppCompatActivity(), OnRobotReadyListener, TtsListener, OnG
         autoRechargeJob = null
     }
 
+    private fun captureReceptionAnchorYawIfNeeded() {
+        if (receptionAnchorYaw != null) {
+            return
+        }
+        val yaw = latestYaw ?: return
+        receptionAnchorYaw = yaw
+        Log.i("MainActivity", "Reception anchor yaw captured: $yaw")
+    }
+
+    private fun recoverReceptionFacingDirection() {
+        if (taskController.currentTask != "reception") {
+            return
+        }
+        val atReceptionLocation = lastArrivalLocation?.equals(taskController.getReceptionLocation(), ignoreCase = true) == true
+        if (!atReceptionLocation) {
+            return
+        }
+        val anchorYaw = receptionAnchorYaw ?: return
+        val currentYaw = latestYaw ?: return
+        val delta = normalizeAngle(anchorYaw - currentYaw)
+        // Ignore tiny drift to avoid jitter.
+        if (kotlin.math.abs(delta) < 8f) {
+            return
+        }
+        val turn = delta.toInt().coerceIn(-45, 45)
+        if (turn == 0) {
+            return
+        }
+        navCon.turnBy(turn, 0.35f)
+        Log.i("MainActivity", "Reception facing recovered by $turn degrees (delta=$delta).")
+    }
+
+    private fun normalizeAngle(angle: Float): Float {
+        var normalized = angle % 360f
+        if (normalized > 180f) {
+            normalized -= 360f
+        } else if (normalized < -180f) {
+            normalized += 360f
+        }
+        return normalized
+    }
+
     private fun updateConnectionIndicator() {
         val colorRes = when {
             !isLiveKitConnected && !isMqttConnected -> android.R.color.holo_red_dark