Optimize large-group probing startup (#6102)

Clear visible delays immediately, but move the per-profile MMKV reset to the existing I/O coroutine. Finish the reset before starting the test service so newly reported results cannot be erased.

V2rayNG/app/src/main/java/com/v2ray/ang/ui/main/MainViewModel.kt

@@ -689,11 +689,17 @@ class MainViewModel(
         dataSource.cancelAllPing()
         val groupId = uiState.value.selectedGroupId
         val servers = currentServers()
-        dataSource.clearAllTestDelayResults(servers.map { it.guid })
         if (servers.isEmpty()) {
             _uiState.update { it.copy(isTesting = false) }
             return
         }
+        val serverGuids = servers.map { it.guid }
+        mutableServersForGroup(groupId).update { current ->
+            current.map { server ->
+                if (server.testDelayMillis == 0L) server
+                else server.copy(testDelayMillis = 0L)
+            }
+        }
         testingGroupId = groupId
         _uiState.update {
             it.copy(
@@ -702,12 +708,13 @@ class MainViewModel(
             )
         }
         viewModelScope.launch(ioDispatcher) {
+            dataSource.clearAllTestDelayResults(serverGuids)
             cacheMutex.withLock { groupDataCache.remove(groupId) }
             dataSource.sendMsg2TestService(
                 TestServiceMessage(
                     key = AppConfig.MSG_MEASURE_CONFIG_START,
                     subscriptionId = groupId,
-                    serverGuids = if (keywordFilter.isNotEmpty()) servers.map { it.guid } else emptyList(),
+                    serverGuids = if (keywordFilter.isNotEmpty()) serverGuids else emptyList(),
                     onlyTcp = onlyTcp
                 )
             )