test: add stable test ids to sign-in fields, tabs and message rows

App.tsx

@@ -297,6 +297,7 @@ function MainTabsNavigator({ navigation }: NativeStackScreenProps<RootStackParam
         name="Mail"
         options={{
           title: tabLabels.mail,
+          tabBarButtonTestID: 'tab-mail',
           tabBarIcon: ({ color, size }) => <Mail size={size} color={color} />,
           tabBarBadge: inboxUnreadCount > 0 ? (inboxUnreadCount > 99 ? '99+' : inboxUnreadCount) : undefined,
           tabBarBadgeStyle: {
@@ -320,6 +321,7 @@ function MainTabsNavigator({ navigation }: NativeStackScreenProps<RootStackParam
         component={CalendarScreen}
         options={{
           title: tabLabels.calendar,
+          tabBarButtonTestID: 'tab-calendar',
           tabBarIcon: ({ color, size }) => <Calendar size={size} color={color} />,
           tabBarItemStyle: hasCalendar ? undefined : disabledTabStyle,
           tabBarAccessibilityLabel: hasCalendar ? tabLabels.calendar : unavailable(tabLabels.calendar),
@@ -335,6 +337,7 @@ function MainTabsNavigator({ navigation }: NativeStackScreenProps<RootStackParam
         component={ContactsTab}
         options={{
           title: tabLabels.contacts,
+          tabBarButtonTestID: 'tab-contacts',
           tabBarIcon: ({ color, size }) => <BookUser size={size} color={color} />,
           tabBarItemStyle: hasContacts ? undefined : disabledTabStyle,
           tabBarAccessibilityLabel: hasContacts ? tabLabels.contacts : unavailable(tabLabels.contacts),
@@ -350,6 +353,7 @@ function MainTabsNavigator({ navigation }: NativeStackScreenProps<RootStackParam
         component={FilesScreen}
         options={{
           title: tabLabels.files,
+          tabBarButtonTestID: 'tab-files',
           tabBarIcon: ({ color, size }) => <HardDrive size={size} color={color} />,
           tabBarItemStyle: hasFiles ? undefined : disabledTabStyle,
           tabBarAccessibilityLabel: hasFiles ? tabLabels.files : unavailable(tabLabels.files),
@@ -364,6 +368,7 @@ function MainTabsNavigator({ navigation }: NativeStackScreenProps<RootStackParam
         name="Settings"
         options={{
           title: tabLabels.settings,
+          tabBarButtonTestID: 'tab-settings',
           tabBarIcon: ({ color, size }) => <Settings size={size} color={color} />,
         }}
       >

src/screens/EmailListScreen.tsx

@@ -176,6 +176,7 @@ const EmailRow = React.memo(function EmailRow({
       onPress={handlePress}
       onLongPress={handleLongPress}
       delayLongPress={300}
+      testID="email-row"
     >
       {unread && (
         <View

src/screens/login/PasswordStep.tsx

@@ -61,6 +61,7 @@ export default function PasswordStep({
         placeholder={t('login.username_placeholder', 'user@example.com')}
         value={email}
         onChangeText={onChangeEmail}
+        testID="login-username-input"
         autoCapitalize="none"
         autoCorrect={false}
         autoComplete="email"
@@ -76,6 +77,7 @@ export default function PasswordStep({
         placeholder={t('login.password_placeholder', 'Enter your password')}
         value={password}
         onChangeText={onChangePassword}
+        testID="login-password-input"
         autoFocus={Boolean(email)}
         secureTextEntry={!showPassword}
         autoComplete="current-password"

src/screens/login/ServerStep.tsx

@@ -61,6 +61,7 @@ export default function ServerStep({
       <Input
         label={t('login.mobile.server_label', 'Server address')}
         placeholder="mail.example.com"
+        testID="login-server-input"
         value={value}
         onChangeText={onChange}
         autoFocus