Audit: form-error TalkBack + focus management + navigateUp polish

(a) liveRegion + error semantics on form error surfaces so TalkBack
    announces them when they appear:
    - Shared ErrorCard (used by LoginScreen, RegisterScreen,
      VerifyEmail/ResetCode, ForgotPassword, ResetPassword)
    - OnboardingCreateAccountContent inline error row
    - JoinResidenceScreen inline error row

(b) focusRequester + ImeAction.Next on multi-field forms:
    - LoginScreen: auto-focus username, Next→password, Done→submit
    - RegisterScreen: auto-focus username, Next chain through
      email/password/confirm, Done on last

(c) navigateUp() replaces navController.popBackStack() for simple back
    actions in App.kt (6 screens) and MainScreen.kt (3 screens), where
    the back behavior is purely navigation-controlled.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composeApp/src/commonMain/kotlin/com/tt/honeyDue/App.kt

@@ -511,7 +511,7 @@ fun App(
 
             composable<JoinResidenceRoute> {
                 com.tt.honeyDue.ui.screens.residence.JoinResidenceScreen(
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                     onJoined = { residenceId ->
                         navController.popBackStack()
                         navController.navigate(ResidenceDetailRoute(residenceId))
@@ -674,7 +674,7 @@ fun App(
             composable<FeatureComparisonRoute> {
                 // P2 Stream E — full-screen Free vs. Pro comparison.
                 FeatureComparisonScreen(
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                     onNavigateToUpgrade = {
                         navController.popBackStack()
                         navController.navigate(UpgradeRoute)
@@ -687,7 +687,7 @@ fun App(
                 val route = backStackEntry.toRoute<TaskSuggestionsRoute>()
                 TaskSuggestionsScreen(
                     residenceId = route.residenceId,
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                 )
             }
 
@@ -696,7 +696,7 @@ fun App(
                 val route = backStackEntry.toRoute<AddTaskWithResidenceRoute>()
                 AddTaskWithResidenceScreen(
                     residenceId = route.residenceId,
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                     onCreated = { navController.popBackStack() },
                 )
             }
@@ -707,7 +707,7 @@ fun App(
                 TaskTemplatesBrowserScreen(
                     residenceId = route.residenceId,
                     fromOnboarding = route.fromOnboarding,
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                 )
             }
 
@@ -734,7 +734,7 @@ fun App(
                         updatedAt = route.updatedAt,
                         completions = emptyList()
                     ),
-                    onNavigateBack = { navController.popBackStack() },
+                    onNavigateBack = { navController.navigateUp() },
                     onTaskUpdated = { navController.popBackStack() }
                 )
             }

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/components/common/ErrorCard.kt

@@ -6,6 +6,10 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.error
+import androidx.compose.ui.semantics.liveRegion
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import com.tt.honeyDue.ui.haptics.Haptics
 import org.jetbrains.compose.ui.tooling.preview.Preview
@@ -22,7 +26,12 @@ fun ErrorCard(
             colors = CardDefaults.cardColors(
                 containerColor = MaterialTheme.colorScheme.errorContainer
             ),
-            modifier = modifier.fillMaxWidth(),
+            modifier = modifier
+                .fillMaxWidth()
+                .semantics {
+                    liveRegion = LiveRegionMode.Polite
+                    error(message)
+                },
             shape = RoundedCornerShape(12.dp)
         ) {
             Text(

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/LoginScreen.kt

@@ -8,12 +8,17 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.*
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
+import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
 import androidx.compose.ui.graphics.Brush
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.focus.FocusDirection
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.platform.LocalFocusManager
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.semantics.testTagsAsResourceId
@@ -51,6 +56,12 @@ fun LoginScreen(
     var googleSignInError by remember { mutableStateOf<String?>(null) }
     val loginState by viewModel.loginState.collectAsStateWithLifecycle()
     val googleSignInState by viewModel.googleSignInState.collectAsStateWithLifecycle()
+    val focusManager = LocalFocusManager.current
+    val usernameFocusRequester = remember { FocusRequester() }
+
+    LaunchedEffect(Unit) {
+        usernameFocusRequester.requestFocus()
+    }
 
     // Handle errors for login
     loginState.HandleErrors(
@@ -139,12 +150,16 @@ fun LoginScreen(
                         },
                         modifier = Modifier
                             .fillMaxWidth()
+                            .focusRequester(usernameFocusRequester)
                             .testTag(AccessibilityIds.Authentication.usernameField),
                         singleLine = true,
                         shape = RoundedCornerShape(OrganicRadius.md),
                         keyboardOptions = KeyboardOptions(
                             keyboardType = KeyboardType.Email,
                             imeAction = ImeAction.Next
+                        ),
+                        keyboardActions = KeyboardActions(
+                            onNext = { focusManager.moveFocus(FocusDirection.Down) }
                         )
                     )
 
@@ -171,7 +186,19 @@ fun LoginScreen(
                             .testTag(AccessibilityIds.Authentication.passwordField),
                         singleLine = true,
                         visualTransformation = if (passwordVisible) VisualTransformation.None else PasswordVisualTransformation(),
-                        shape = RoundedCornerShape(OrganicRadius.md)
+                        shape = RoundedCornerShape(OrganicRadius.md),
+                        keyboardOptions = KeyboardOptions(
+                            keyboardType = KeyboardType.Password,
+                            imeAction = ImeAction.Done
+                        ),
+                        keyboardActions = KeyboardActions(
+                            onDone = {
+                                focusManager.clearFocus()
+                                if (username.isNotEmpty() && password.isNotEmpty()) {
+                                    viewModel.login(username, password)
+                                }
+                            }
+                        )
                     )
 
                     ErrorCard(message = errorMessage)

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/MainScreen.kt

@@ -155,7 +155,7 @@ fun MainScreen(
                 composable<JoinResidenceRoute> {
                     Box(modifier = Modifier.fillMaxSize()) {
                         com.tt.honeyDue.ui.screens.residence.JoinResidenceScreen(
-                            onNavigateBack = { navController.popBackStack() },
+                            onNavigateBack = { navController.navigateUp() },
                             onJoined = { residenceId ->
                                 // Pop the join screen and hand off to the
                                 // parent nav graph (ResidenceDetailRoute lives
@@ -242,7 +242,7 @@ fun MainScreen(
                     AddDocumentScreen(
                         residenceId = route.residenceId,
                         initialDocumentType = route.initialDocumentType,
-                        onNavigateBack = { navController.popBackStack() },
+                        onNavigateBack = { navController.navigateUp() },
                         onDocumentCreated = {
                             navController.popBackStack()
                         }
@@ -253,7 +253,7 @@ fun MainScreen(
                     val route = backStackEntry.toRoute<DocumentDetailRoute>()
                     DocumentDetailScreen(
                         documentId = route.documentId,
-                        onNavigateBack = { navController.popBackStack() },
+                        onNavigateBack = { navController.navigateUp() },
                         onNavigateToEdit = { documentId ->
                             navController.navigate(EditDocumentRoute(documentId))
                         }
@@ -264,7 +264,7 @@ fun MainScreen(
                     val route = backStackEntry.toRoute<EditDocumentRoute>()
                     EditDocumentScreen(
                         documentId = route.documentId,
-                        onNavigateBack = { navController.popBackStack() }
+                        onNavigateBack = { navController.navigateUp() }
                     )
                 }
 

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/RegisterScreen.kt

@@ -3,6 +3,8 @@ package com.tt.honeyDue.ui.screens
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.text.KeyboardActions
+import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.*
@@ -11,10 +13,16 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusDirection
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.platform.LocalFocusManager
 import androidx.compose.ui.platform.testTag
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.semantics.testTagsAsResourceId
 import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.input.ImeAction
+import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
@@ -47,6 +55,12 @@ fun RegisterScreen(
     var isLoading by remember { mutableStateOf(false) }
 
     val createState by viewModel.registerState.collectAsStateWithLifecycle()
+    val focusManager = LocalFocusManager.current
+    val usernameFocusRequester = remember { FocusRequester() }
+
+    LaunchedEffect(Unit) {
+        usernameFocusRequester.requestFocus()
+    }
 
     // Handle errors for registration
     createState.HandleErrors(
@@ -130,9 +144,14 @@ fun RegisterScreen(
                             },
                             modifier = Modifier
                                 .fillMaxWidth()
+                                .focusRequester(usernameFocusRequester)
                                 .testTag(AccessibilityIds.Authentication.registerUsernameField),
                             singleLine = true,
-                            shape = RoundedCornerShape(AppRadius.md)
+                            shape = RoundedCornerShape(AppRadius.md),
+                            keyboardOptions = KeyboardOptions(imeAction = ImeAction.Next),
+                            keyboardActions = KeyboardActions(
+                                onNext = { focusManager.moveFocus(FocusDirection.Down) }
+                            )
                         )
 
                         OutlinedTextField(
@@ -146,7 +165,14 @@ fun RegisterScreen(
                                 .fillMaxWidth()
                                 .testTag(AccessibilityIds.Authentication.registerEmailField),
                             singleLine = true,
-                            shape = RoundedCornerShape(AppRadius.md)
+                            shape = RoundedCornerShape(AppRadius.md),
+                            keyboardOptions = KeyboardOptions(
+                                keyboardType = KeyboardType.Email,
+                                imeAction = ImeAction.Next
+                            ),
+                            keyboardActions = KeyboardActions(
+                                onNext = { focusManager.moveFocus(FocusDirection.Down) }
+                            )
                         )
 
                         OrganicDivider()
@@ -163,7 +189,14 @@ fun RegisterScreen(
                                 .testTag(AccessibilityIds.Authentication.registerPasswordField),
                             singleLine = true,
                             visualTransformation = PasswordVisualTransformation(),
-                            shape = RoundedCornerShape(AppRadius.md)
+                            shape = RoundedCornerShape(AppRadius.md),
+                            keyboardOptions = KeyboardOptions(
+                                keyboardType = KeyboardType.Password,
+                                imeAction = ImeAction.Next
+                            ),
+                            keyboardActions = KeyboardActions(
+                                onNext = { focusManager.moveFocus(FocusDirection.Down) }
+                            )
                         )
 
                         OutlinedTextField(
@@ -178,7 +211,14 @@ fun RegisterScreen(
                                 .testTag(AccessibilityIds.Authentication.registerConfirmPasswordField),
                             singleLine = true,
                             visualTransformation = PasswordVisualTransformation(),
-                            shape = RoundedCornerShape(AppRadius.md)
+                            shape = RoundedCornerShape(AppRadius.md),
+                            keyboardOptions = KeyboardOptions(
+                                keyboardType = KeyboardType.Password,
+                                imeAction = ImeAction.Done
+                            ),
+                            keyboardActions = KeyboardActions(
+                                onDone = { focusManager.clearFocus() }
+                            )
                         )
                     }
                 }

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/onboarding/OnboardingCreateAccountContent.kt

@@ -15,6 +15,10 @@ import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.error
+import androidx.compose.ui.semantics.liveRegion
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.style.TextAlign
@@ -240,7 +244,12 @@ fun OnboardingCreateAccountContent(
                     // Error message
                     if (localErrorMessage != null) {
                         OrganicCard(
-                            modifier = Modifier.fillMaxWidth(),
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .semantics {
+                                    liveRegion = LiveRegionMode.Polite
+                                    error(localErrorMessage ?: "")
+                                },
                             accentColor = MaterialTheme.colorScheme.error,
                             showBlob = false
                         ) {

composeApp/src/commonMain/kotlin/com/tt/honeyDue/ui/screens/residence/JoinResidenceScreen.kt

@@ -35,6 +35,9 @@ import androidx.compose.runtime.getValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.testTag
+import androidx.compose.ui.semantics.LiveRegionMode
+import androidx.compose.ui.semantics.error
+import androidx.compose.ui.semantics.liveRegion
 import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.semantics.testTagsAsResourceId
 import androidx.compose.ui.text.font.FontWeight
@@ -160,7 +163,11 @@ fun JoinResidenceScreen(
                     Row(
                         modifier = Modifier
                             .fillMaxWidth()
-                            .padding(AppSpacing.sm),
+                            .padding(AppSpacing.sm)
+                            .semantics {
+                                liveRegion = LiveRegionMode.Polite
+                                error(error ?: "")
+                            },
                         verticalAlignment = Alignment.CenterVertically,
                         horizontalArrangement = Arrangement.spacedBy(AppSpacing.sm),
                     ) {