Add validation tests for invalid credentials and offline user login

.maestro/flows/001_001_invite_users_using_qr_code_or_link_test.yaml

@@ -202,13 +202,42 @@ onFlowComplete:
     file: "subflows/get_started_select_school_by_name.yaml"
     env:
       SCHOOL_NAME: ${SCHOOL_NAME}
+# Test login error when login credential is not valid - Invalid username
 - tapOn:
     id: "username"
-- inputText: "teacherauser"
+- inputText: "teacheruser"
 - tapOn:
     id : "password"
 - inputText: "test123"
 - tapOn: "Login"
+- assertVisible: "Invalid username/password"
+- runFlow:
+    file: "subflows/erase_text.yaml"
+    env:
+      TEXT: "teacheruser"
+
+# Test error when device internet is not connected
+- setAirplaneMode: enabled
+- extendedWaitUntil:
+    visible:
+      id: "internet_disconnected"
+    timeout: 10000
+- tapOn:
+    id : "username"
+- inputText: "teacherauser"
+- tapOn: "Login"
+- assertVisible: "Network error: check your connection and try again"
+
+# Device back to Online mode - Login success
+- setAirplaneMode: disabled
+- extendedWaitUntil:
+    visible:
+      id: "internet_connected"
+    timeout: 10000
+- assertVisible:
+    id: "app_title"
+    text: "Login"
+- tapOn: "Login"
 - assertVisible:
          id: "nav_home"
 - tapOn: "Classes"

respect-app-compose/src/commonMain/kotlin/world/respect/app/app/App.kt

@@ -34,6 +34,7 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.navigation.compose.rememberNavController
+import com.ustadmobile.libcache.connectivitymonitor.ConnectivityMonitor
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
@@ -162,8 +163,10 @@ fun App(
     val coroutineScope = rememberCoroutineScope()
 
     val accountManager: RespectAccountManager = koinInject()
+    val connectivityMonitor: ConnectivityMonitor = koinInject()
     val biometricAuthUseCase : BiometricAuthUseCase = koinInject()
     val activeAccount by accountManager.selectedAccountAndPersonFlow.collectAsState(null)
+    val connectivityState by connectivityMonitor.statusFlow.collectAsState()
     val topLevelNavItems = if (activeAccount?.isChild == true) {
         APP_TOP_LEVEL_NAV_ITEMS_FOR_CHILD
     } else {
@@ -209,6 +212,7 @@ fun App(
                         RespectAppBar(
                             compactHeader = (widthClass != SizeClass.EXPANDED),
                             appUiState = appUiStateVal,
+                            isConnectedToInternet = connectivityState.isConnected,
                             navController = navController,
                             topLevelItems = topLevelNavItems,
                             onProfileClick = {

respect-app-compose/src/commonMain/kotlin/world/respect/app/app/AppBar.kt

@@ -1,6 +1,7 @@
 package world.respect.app.app
 
 import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.width
@@ -65,11 +66,16 @@ import world.respect.shared.viewmodel.app.appstate.AppUiState
 import world.respect.shared.viewmodel.app.appstate.LoadingUiState
 
 
+const val INTERNET_CONNECTED_TAG = "internet_connected"
+
+const val INTERNET_DISCONNECTED_TAG = "internet_disconnected"
+
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
 fun RespectAppBar(
     compactHeader: Boolean,
     appUiState: AppUiState,
+    isConnectedToInternet: Boolean,
     navController: NavController,
     onProfileClick: () -> Unit = {},
     topLevelItems: List<TopNavigationItem>,
@@ -131,6 +137,19 @@ fun RespectAppBar(
     Box(
         contentAlignment = Alignment.BottomCenter
     ) {
+        Spacer(
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(1.dp)
+                .testTag(
+                    if (isConnectedToInternet) {
+                        INTERNET_CONNECTED_TAG
+                    } else {
+                        INTERNET_DISCONNECTED_TAG
+                    }
+                )
+        )
+
         TopAppBar(
             title = {
                 Text(