fix(activity): 修复 queryUserCount 在主线程执行 Room 查询导致崩溃的问题

- DB 查询改用 withContext(Dispatchers.IO) 切换至 IO 线程
- clearFace/clearFaceAndGetAll 操作完成后自动刷新用户计数
- 删除未使用的 CoroutineDispatcher import

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

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

@@ -10,7 +10,6 @@ import com.sw.platecabinet.dialog.CustomDialog
 import com.sw.platecabinet.ext.clickWithDebounce
 import com.sw.platecabinet.utils.PlateUtils
 import com.sw.platecabinet.utils.SpTool
-import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
@@ -45,6 +44,7 @@ class FunActivity : BaseActivity<ActivityFunBinding>() {
                     {
                         hideWaitingDialog()
                         ToastUtils.showToast("已清除")
+                        queryUserCount()
                     }, 500
                 )
             }
@@ -60,6 +60,7 @@ class FunActivity : BaseActivity<ActivityFunBinding>() {
                     ToastUtils.showToast(
                         if (status) "请求成功，$msg" else "请求失败，$msg"
                     )
+                    queryUserCount()
                 }
             }
         }
@@ -117,8 +118,8 @@ class FunActivity : BaseActivity<ActivityFunBinding>() {
     private fun queryUserCount() {
         lifecycleScope.launch {
             val faceDao = FaceDatabase.getInstance(this@FunActivity).faceDao()
-            val memberUserCount = faceDao.getFaceCount("1")
-            val tempUserCount = faceDao.getFaceCount("2")
+            val memberUserCount = withContext(Dispatchers.IO) { faceDao.getFaceCount("1") }
+            val tempUserCount = withContext(Dispatchers.IO) { faceDao.getFaceCount("2") }
             binding.tvMemberUserCount.text = "会员用户：${memberUserCount}人"
             binding.tvTempUserCount.text = "临时用户：${tempUserCount}人"
         }