Add auto-login after password reset on iOS and Android

- Add LOGGING_IN step to PasswordResetStep enum on both platforms
- Auto-login with new credentials after successful password reset
- Navigate directly to main app (or verification screen if unverified)
- Show "Logging in..." state during auto-login process
- Hide back button during auto-login to prevent interruption
- Fall back to "Return to Login" if auto-login fails

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

composeApp/src/commonMain/kotlin/com/example/casera/ui/screens/ResetPasswordScreen.kt

@@ -36,6 +36,7 @@ fun ResetPasswordScreen(
     var confirmPasswordVisible by remember { mutableStateOf(false) }
 
     val resetPasswordState by viewModel.resetPasswordState.collectAsState()
+    val loginState by viewModel.loginState.collectAsState()
     val currentStep by viewModel.currentStep.collectAsState()
 
     // Handle errors for password reset
@@ -50,6 +51,7 @@ fun ResetPasswordScreen(
     }
 
     val isLoading = resetPasswordState is ApiResult.Loading
+    val isLoggingIn = currentStep == com.example.casera.viewmodel.PasswordResetStep.LOGGING_IN
     val isSuccess = currentStep == com.example.casera.viewmodel.PasswordResetStep.SUCCESS
 
     // Password validation
@@ -63,9 +65,12 @@ fun ResetPasswordScreen(
             TopAppBar(
                 title = { Text(stringResource(Res.string.auth_reset_title)) },
                 navigationIcon = {
-                    onNavigateBack?.let { callback ->
-                        IconButton(onClick = callback) {
-                            Icon(Icons.Default.ArrowBack, contentDescription = stringResource(Res.string.common_back))
+                    // Hide back button while logging in
+                    if (!isLoggingIn) {
+                        onNavigateBack?.let { callback ->
+                            IconButton(onClick = callback) {
+                                Icon(Icons.Default.ArrowBack, contentDescription = stringResource(Res.string.common_back))
+                            }
                         }
                     }
                 },
@@ -239,15 +244,21 @@ fun ResetPasswordScreen(
                             modifier = Modifier
                                 .fillMaxWidth()
                                 .height(56.dp),
-                            enabled = isFormValid && !isLoading,
+                            enabled = isFormValid && !isLoading && !isLoggingIn,
                             shape = RoundedCornerShape(12.dp)
                         ) {
-                            if (isLoading) {
+                            if (isLoading || isLoggingIn) {
                                 CircularProgressIndicator(
                                     modifier = Modifier.size(24.dp),
                                     color = MaterialTheme.colorScheme.onPrimary,
                                     strokeWidth = 2.dp
                                 )
+                                Spacer(modifier = Modifier.width(8.dp))
+                                Text(
+                                    if (isLoggingIn) "Logging in..." else "Resetting...",
+                                    style = MaterialTheme.typography.titleMedium,
+                                    fontWeight = FontWeight.SemiBold
+                                )
                             } else {
                                 Icon(Icons.Default.LockReset, contentDescription = null)
                                 Spacer(modifier = Modifier.width(8.dp))