feat(02-03): build task list screen with task row, completion, and overdue highlighting

- TaskListScreen with room name in AppBar, edit/delete room actions
- AsyncValue.when for loading/error/data states with empty state
- TaskRow with leading checkbox, name, German relative due date, frequency label
- Overdue dates highlighted in warm coral (0xFFE07A5F)
- Checkbox marks done immediately (optimistic UI, no undo)
- Row tap navigates to edit form, long-press shows delete confirmation
- FAB for creating new tasks
- ListView.builder for task list sorted by due date

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/features/tasks/presentation/task_list_screen.dart

@@ -1,17 +1,228 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
 
-/// Placeholder for the task list screen within a room.
+import 'package:household_keeper/core/database/database.dart';
-/// Will be fully implemented in Plan 03.
+import 'package:household_keeper/core/providers/database_provider.dart';
-class TaskListScreen extends StatelessWidget {
+import 'package:household_keeper/features/tasks/presentation/task_providers.dart';
+import 'package:household_keeper/features/tasks/presentation/task_row.dart';
+import 'package:household_keeper/l10n/app_localizations.dart';
+
+/// Screen displaying all tasks within a room, sorted by due date.
+///
+/// Shows an empty state when no tasks exist, with a button to create one.
+/// FAB always visible for quick task creation.
+/// AppBar shows room name with edit and delete actions.
+class TaskListScreen extends ConsumerWidget {
   const TaskListScreen({super.key, required this.roomId});
 
   final int roomId;
 
   @override
-  Widget build(BuildContext context) {
+  Widget build(BuildContext context, WidgetRef ref) {
+    final l10n = AppLocalizations.of(context);
+    final asyncTasks = ref.watch(tasksInRoomProvider(roomId));
+
     return Scaffold(
-      appBar: AppBar(title: const Text('Aufgaben')),
+      appBar: AppBar(
-      body: const Center(child: Text('Demnächst verfügbar')),
+        title: _RoomTitle(roomId: roomId),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.edit),
+            onPressed: () => context.go('/rooms/$roomId/edit'),
+          ),
+          IconButton(
+            icon: const Icon(Icons.delete),
+            onPressed: () => _showRoomDeleteConfirmation(context, ref, l10n),
+          ),
+        ],
+      ),
+      body: asyncTasks.when(
+        data: (tasks) {
+          if (tasks.isEmpty) {
+            return _EmptyState(l10n: l10n, roomId: roomId);
+          }
+          return _TaskListView(
+            tasks: tasks,
+            l10n: l10n,
+          );
+        },
+        loading: () => const Center(child: CircularProgressIndicator()),
+        error: (error, stack) => Center(
+          child: Column(
+            mainAxisSize: MainAxisSize.min,
+            children: [
+              Text('Fehler: $error'),
+              const SizedBox(height: 16),
+              FilledButton.tonal(
+                onPressed: () => ref.invalidate(tasksInRoomProvider(roomId)),
+                child: const Text('Erneut versuchen'),
+              ),
+            ],
+          ),
+        ),
+      ),
+      floatingActionButton: FloatingActionButton(
+        onPressed: () => context.go('/rooms/$roomId/tasks/new'),
+        child: const Icon(Icons.add),
+      ),
+    );
+  }
+
+  void _showRoomDeleteConfirmation(
+    BuildContext context,
+    WidgetRef ref,
+    AppLocalizations l10n,
+  ) {
+    showDialog(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: Text(l10n.roomDeleteConfirmTitle),
+        content: Text(l10n.roomDeleteConfirmMessage),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx),
+            child: Text(l10n.cancel),
+          ),
+          FilledButton(
+            onPressed: () {
+              Navigator.pop(ctx);
+              final db = ref.read(appDatabaseProvider);
+              db.roomsDao.deleteRoom(roomId);
+              // Navigate back to rooms list
+              context.go('/rooms');
+            },
+            style: FilledButton.styleFrom(
+              backgroundColor: Theme.of(context).colorScheme.error,
+              foregroundColor: Theme.of(context).colorScheme.onError,
+            ),
+            child: Text(l10n.roomDeleteConfirmAction),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+/// Async room name loader for the AppBar title.
+class _RoomTitle extends ConsumerWidget {
+  const _RoomTitle({required this.roomId});
+
+  final int roomId;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    // Use a FutureBuilder-like approach: read room name from DB
+    return FutureBuilder<Room>(
+      future: ref.read(appDatabaseProvider).roomsDao.getRoomById(roomId),
+      builder: (context, snapshot) {
+        if (snapshot.hasData) {
+          return Text(snapshot.data!.name);
+        }
+        return const Text('...');
+      },
+    );
+  }
+}
+
+/// Empty state shown when the room has no tasks.
+class _EmptyState extends StatelessWidget {
+  const _EmptyState({required this.l10n, required this.roomId});
+
+  final AppLocalizations l10n;
+  final int roomId;
+
+  @override
+  Widget build(BuildContext context) {
+    final theme = Theme.of(context);
+
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 32),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Icon(
+              Icons.task_alt,
+              size: 80,
+              color: theme.colorScheme.onSurface.withValues(alpha: 0.4),
+            ),
+            const SizedBox(height: 24),
+            Text(
+              l10n.taskEmptyTitle,
+              style: theme.textTheme.headlineSmall,
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 8),
+            Text(
+              l10n.taskEmptyMessage,
+              style: theme.textTheme.bodyLarge?.copyWith(
+                color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
+              ),
+              textAlign: TextAlign.center,
+            ),
+            const SizedBox(height: 24),
+            FilledButton.tonal(
+              onPressed: () => context.go('/rooms/$roomId/tasks/new'),
+              child: Text(l10n.taskEmptyAction),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+/// List view of task rows with long-press delete support.
+class _TaskListView extends ConsumerWidget {
+  const _TaskListView({required this.tasks, required this.l10n});
+
+  final List<Task> tasks;
+  final AppLocalizations l10n;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    return ListView.builder(
+      itemCount: tasks.length,
+      itemBuilder: (context, index) {
+        final task = tasks[index];
+        return TaskRow(
+          key: ValueKey(task.id),
+          task: task,
+          onDelete: () => _showDeleteConfirmation(context, ref, task),
+        );
+      },
+    );
+  }
+
+  void _showDeleteConfirmation(
+    BuildContext context,
+    WidgetRef ref,
+    Task task,
+  ) {
+    showDialog(
+      context: context,
+      builder: (ctx) => AlertDialog(
+        title: Text(l10n.taskDeleteConfirmTitle),
+        content: Text(l10n.taskDeleteConfirmMessage),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.pop(ctx),
+            child: Text(l10n.cancel),
+          ),
+          FilledButton(
+            onPressed: () {
+              Navigator.pop(ctx);
+              ref.read(taskActionsProvider.notifier).deleteTask(task.id);
+            },
+            style: FilledButton.styleFrom(
+              backgroundColor: Theme.of(context).colorScheme.error,
+              foregroundColor: Theme.of(context).colorScheme.onError,
+            ),
+            child: Text(l10n.taskDeleteConfirmAction),
+          ),
+        ],
+      ),
     );
   }
 }

lib/features/tasks/presentation/task_row.dart

@@ -0,0 +1,106 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
+
+import 'package:household_keeper/core/database/database.dart';
+import 'package:household_keeper/features/tasks/domain/frequency.dart';
+import 'package:household_keeper/features/tasks/domain/relative_date.dart';
+import 'package:household_keeper/features/tasks/presentation/task_providers.dart';
+
+/// Warm coral/terracotta color for overdue due date text.
+const _overdueColor = Color(0xFFE07A5F);
+
+/// A single task row with leading checkbox, name, relative due date,
+/// and frequency label.
+///
+/// Per user decisions:
+/// - Checkbox marks task done immediately (optimistic UI, no undo)
+/// - Row tap opens edit form
+/// - No swipe gesture
+/// - No effort indicator or description preview on list view
+/// - Overdue: due date text turns warm coral, rest stays normal
+class TaskRow extends ConsumerWidget {
+  const TaskRow({
+    super.key,
+    required this.task,
+    this.onDelete,
+  });
+
+  final Task task;
+  final VoidCallback? onDelete;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final theme = Theme.of(context);
+    final now = DateTime.now();
+    final today = DateTime(now.year, now.month, now.day);
+
+    // Check if task is overdue (due date is before today)
+    final dueDate = DateTime(
+      task.nextDueDate.year,
+      task.nextDueDate.month,
+      task.nextDueDate.day,
+    );
+    final isOverdue = dueDate.isBefore(today);
+
+    // Format relative due date in German
+    final relativeDateText = formatRelativeDate(task.nextDueDate, now);
+
+    // Build frequency label
+    final freq = FrequencyInterval(
+      intervalType: task.intervalType,
+      days: task.intervalDays,
+    );
+    final frequencyText = freq.label();
+
+    return ListTile(
+      leading: Checkbox(
+        value: false, // Always unchecked -- completion is immediate + reschedule
+        onChanged: (_) {
+          // Mark done immediately (optimistic UI, no undo per user decision)
+          ref.read(taskActionsProvider.notifier).completeTask(task.id);
+        },
+      ),
+      title: Text(
+        task.name,
+        style: theme.textTheme.titleMedium,
+        maxLines: 1,
+        overflow: TextOverflow.ellipsis,
+      ),
+      subtitle: Row(
+        children: [
+          Text(
+            relativeDateText,
+            style: theme.textTheme.bodySmall?.copyWith(
+              color: isOverdue ? _overdueColor : theme.colorScheme.onSurfaceVariant,
+            ),
+          ),
+          Padding(
+            padding: const EdgeInsets.symmetric(horizontal: 6),
+            child: Text(
+              '\u00b7', // middle dot separator
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurfaceVariant,
+              ),
+            ),
+          ),
+          Flexible(
+            child: Text(
+              frequencyText,
+              style: theme.textTheme.bodySmall?.copyWith(
+                color: theme.colorScheme.onSurfaceVariant,
+              ),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+            ),
+          ),
+        ],
+      ),
+      onTap: () {
+        // Tap row opens edit form
+        context.go('/rooms/${task.roomId}/tasks/${task.id}');
+      },
+      onLongPress: onDelete,
+    );
+  }
+}