fix: Dark Mode visibility for DatePicker and TimePicker dialogs

Fixed issues where DatePicker and TimePicker dialogs were not visible
in Dark Mode due to white text on white background. Applied proper
theming to ensure text contrast in both light and dark modes.

Changes:
- Settings page: Birth date picker now uses DatePickerThemeData
- Health Mode setup: Date picker theming for pause start date
- Comeback setup: Date picker theming for illness start date
- Workout scheduler: Date and time picker theming for workout scheduling
- Fixed StrengthWorkoutDao method call: getWorkout → getWorkoutById

All date/time pickers now respect the current theme and display properly
in Dark Mode with correct text colors and contrast.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: sprobst76

lib/data/mappers/scheduled_workout_mapper.dart

@@ -28,7 +28,7 @@ class ScheduledWorkoutMapper {
         createdAt: entity.createdAt,
       );
     } else {
-      final workout = await _strengthWorkoutDao.getWorkout(entity.workoutId);
+      final workout = await _strengthWorkoutDao.getWorkoutById(entity.workoutId);
 
       return ScheduledWorkout(
         id: entity.id,

lib/features/comeback/presentation/pages/comeback_setup_page.dart

@@ -295,6 +295,26 @@ class _ComebackSetupPageState extends ConsumerState<ComebackSetupPage> {
       initialDate: _illnessStartDate ?? DateTime.now().subtract(const Duration(days: 7)),
       firstDate: DateTime.now().subtract(const Duration(days: 60)),
       lastDate: DateTime.now(),
+      builder: (context, child) {
+        return Theme(
+          data: Theme.of(context).copyWith(
+            useMaterial3: true,
+            datePickerTheme: DatePickerThemeData(
+              backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+              elevation: 8,
+              headerBackgroundColor: AppColors.primary,
+              headerForegroundColor: Colors.white,
+              weekdayStyle: const TextStyle(
+                color: AppColors.textPrimary,
+                fontWeight: FontWeight.bold,
+              ),
+              dayStyle: const TextStyle(color: AppColors.textPrimary),
+              yearStyle: const TextStyle(color: AppColors.textPrimary),
+            ),
+          ),
+          child: child ?? const SizedBox(),
+        );
+      },
     );
     if (date != null) {
       setState(() => _illnessStartDate = date);

lib/features/health_mode/presentation/pages/health_mode_setup_page.dart

@@ -343,6 +343,26 @@ class _HealthModeSetupPageState extends ConsumerState<HealthModeSetupPage> {
       initialDate: _pauseStartDate ?? DateTime.now().subtract(const Duration(days: 7)),
       firstDate: DateTime.now().subtract(const Duration(days: 60)),
       lastDate: DateTime.now(),
+      builder: (context, child) {
+        return Theme(
+          data: Theme.of(context).copyWith(
+            useMaterial3: true,
+            datePickerTheme: DatePickerThemeData(
+              backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+              elevation: 8,
+              headerBackgroundColor: AppColors.primary,
+              headerForegroundColor: Colors.white,
+              weekdayStyle: const TextStyle(
+                color: AppColors.textPrimary,
+                fontWeight: FontWeight.bold,
+              ),
+              dayStyle: const TextStyle(color: AppColors.textPrimary),
+              yearStyle: const TextStyle(color: AppColors.textPrimary),
+            ),
+          ),
+          child: child ?? const SizedBox(),
+        );
+      },
     );
     if (date != null) {
       setState(() => _pauseStartDate = date);

lib/features/settings/presentation/pages/settings_page.dart

@@ -526,6 +526,26 @@ class SettingsPage extends ConsumerWidget {
       firstDate: DateTime(1950),
       lastDate: DateTime.now(),
       locale: const Locale('de', 'DE'),
+      builder: (context, child) {
+        return Theme(
+          data: Theme.of(context).copyWith(
+            useMaterial3: true,
+            datePickerTheme: DatePickerThemeData(
+              backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+              elevation: 8,
+              headerBackgroundColor: AppColors.primary,
+              headerForegroundColor: Colors.white,
+              weekdayStyle: const TextStyle(
+                color: AppColors.textPrimary,
+                fontWeight: FontWeight.bold,
+              ),
+              dayStyle: const TextStyle(color: AppColors.textPrimary),
+              yearStyle: const TextStyle(color: AppColors.textPrimary),
+            ),
+          ),
+          child: child ?? const SizedBox(),
+        );
+      },
     );
 
     if (pickedDate != null) {

lib/features/workout_scheduler/presentation/widgets/schedule_workout_dialog.dart

@@ -106,6 +106,26 @@ class __ScheduleWorkoutDialogState
       firstDate: DateTime.now(),
       lastDate: DateTime.now().add(const Duration(days: 365)),
       locale: const Locale('de', 'DE'),
+      builder: (context, child) {
+        return Theme(
+          data: Theme.of(context).copyWith(
+            useMaterial3: true,
+            datePickerTheme: DatePickerThemeData(
+              backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+              elevation: 8,
+              headerBackgroundColor: AppColors.primary,
+              headerForegroundColor: Colors.white,
+              weekdayStyle: const TextStyle(
+                color: AppColors.textPrimary,
+                fontWeight: FontWeight.bold,
+              ),
+              dayStyle: const TextStyle(color: AppColors.textPrimary),
+              yearStyle: const TextStyle(color: AppColors.textPrimary),
+            ),
+          ),
+          child: child ?? const SizedBox(),
+        );
+      },
     );
 
     if (date != null) {
@@ -117,6 +137,23 @@ class __ScheduleWorkoutDialogState
     final time = await showTimePicker(
       context: context,
       initialTime: TimeOfDay.now(),
+      builder: (context, child) {
+        return Theme(
+          data: Theme.of(context).copyWith(
+            useMaterial3: true,
+            timePickerTheme: TimePickerThemeData(
+              backgroundColor: Theme.of(context).scaffoldBackgroundColor,
+              hourMinuteTextColor: AppColors.textPrimary,
+              hourMinuteColor: AppColors.primary.withValues(alpha: 0.1),
+              dialHandColor: AppColors.primary,
+              dialBackgroundColor: AppColors.surfaceLight,
+              entryModeIconColor: AppColors.textSecondary,
+              helpTextStyle: const TextStyle(color: AppColors.textPrimary),
+            ),
+          ),
+          child: child ?? const SizedBox(),
+        );
+      },
     );
 
     if (time != null) {