refactor(face): 重构倒计时工具，统一使用 CountDownUtil 实例化方案

- CountDownUtil 由 object 单例改为 class，各调用方持有独立实例，互不干扰
- 修复 onCompletion 取消时误触发 onFinish 的 bug
- LoginByFaceActivity 新增 recognizeCountDownUtil / leftCountDownUtil 两个实例
- 移除 CountDownManager 及其所有调用，消除两套倒计时并存的混乱

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/java/com/sw/platecabinet/activity/LoginByFaceActivity.kt

@@ -49,7 +49,6 @@ import com.sw.platecabinet.ext.visible
 import com.sw.platecabinet.model.response.EquipmentUserInfo
 import com.sw.platecabinet.model.response.UserFaceModel
 import com.sw.platecabinet.utils.BitmapSaver
-import com.sw.platecabinet.utils.CountDownManager
 import com.sw.platecabinet.utils.CountDownUtil
 import com.sw.platecabinet.utils.Debouncer
 import com.sw.platecabinet.utils.LogFileUtil
@@ -169,6 +168,12 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
 
     private val leftDebouncer = Debouncer(30 * 1000)
 
+    /** 识别超时倒计时（15秒无操作跳回初始页） */
+    private val recognizeCountDownUtil = CountDownUtil()
+
+    /** 用户离开画面后的倒计时（llCollectButton 显示状态下无人脸时触发） */
+    private val leftCountDownUtil = CountDownUtil()
+
     private var registerHandler: RegisterCallbackHandler? = null
 
     private fun isFitData(userFaceInfo: UserFaceInfo?): Boolean {
@@ -331,7 +336,7 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
     }
 
     private fun recognizeFail() {
-        CountDownManager.cancelCountDown()
+        recognizeCountDownUtil.cancelCountDown()
         binding.tvToInit.text = ""
         binding.tvSimilarValue.text = ""
         binding.llCollectButton.visible()
@@ -389,7 +394,7 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
                 PlateUtils.open(this, item.equipmentBoxCode, false) {
                     goInitActivity()
                 }
-                CountDownManager.cancelCountDown()
+                recognizeCountDownUtil.cancelCountDown()
             }
             currentPlateInfo = item
             MyApp.plateList = items
@@ -699,8 +704,9 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
         resumeCamera()
         registerHandler = RegisterCallbackHandler()
 
-        CountDownManager.startCountDown(
-            totalSeconds = 15,
+        recognizeCountDownUtil.startCountDown(
+            total = 15,
+            lifecycleScope = lifecycleScope,
             onTick = { remaining ->
                 loadLogInfo("resetRecognizeState剩余时间：$remaining 秒")
                 if (judgeRecognizeState()) return@startCountDown
@@ -725,7 +731,7 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
     override fun onPause() {
         pauseCamera()
         super.onPause()
-        CountDownManager.cancelCountDown()
+        recognizeCountDownUtil.cancelCountDown()
     }
 
     private fun pauseCamera() {
@@ -883,19 +889,18 @@ class LoginByFaceActivity : BaseActivity<ActivityLoginFaceBinding>(),
 
     private var isCollectFace = false
     private fun leftCountDown() {
-        CountDownUtil.startCountDown(total = 15, lifecycleScope = lifecycleScope, onStart = {
+        leftCountDownUtil.startCountDown(total = 15, lifecycleScope = lifecycleScope, onStart = {
             loadLogInfo("onPreview-----------leftCountDown-------------")
         }, onTick = {
             loadLogInfo("leftCountDown.onTick:$it")
             if (facePreviewInfoList.isNullOrEmpty().not()) {
                 loadLogInfo("leftCountDown.onTick-cancel()")
-                CountDownUtil.cancelCountDown()
+                leftCountDownUtil.cancelCountDown()
                 return@startCountDown
             }
         }, onFinish = {
-            CountDownUtil.cancelCountDown()
             if (facePreviewInfoList.isNullOrEmpty().not()) {
-                loadLogInfo("leftCountDown.onFinish-cancel()")
+                loadLogInfo("leftCountDown.onFinish-人脸未离开，不跳转")
                 return@startCountDown
             }
             goInitActivity()