feat(05-02): replace HomeScreen with calendar composition and floating Today button

- Rewrite HomeScreen as ConsumerStatefulWidget composing CalendarStrip + CalendarDayList
- CalendarStripController wires floating Today button to scroll-strip-to-today animation
- FloatingActionButton.extended shows "Heute" + Icons.today only when today is out of viewport
- Old overdue/today/tomorrow stacked plan sections and ProgressCard fully removed

lib/features/home/presentation/home_screen.dart

@@ -1,22 +1,16 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
-import 'package:go_router/go_router.dart';
 
-import 'package:household_keeper/features/home/domain/daily_plan_models.dart';
-import 'package:household_keeper/features/home/presentation/daily_plan_providers.dart';
-import 'package:household_keeper/features/home/presentation/daily_plan_task_row.dart';
-import 'package:household_keeper/features/home/presentation/progress_card.dart';
-import 'package:household_keeper/features/tasks/presentation/task_providers.dart';
+import 'package:household_keeper/features/home/presentation/calendar_day_list.dart';
+import 'package:household_keeper/features/home/presentation/calendar_providers.dart';
+import 'package:household_keeper/features/home/presentation/calendar_strip.dart';
 import 'package:household_keeper/l10n/app_localizations.dart';
 
-/// Warm coral/terracotta color for overdue section header.
-const _overdueColor = Color(0xFFE07A5F);
-
-/// The app's primary screen: daily plan showing what's due today,
-/// overdue tasks, and a preview of tomorrow.
+/// The app's primary screen: a horizontal calendar strip at the top with a
+/// day task list below.
 ///
-/// Replaces the former placeholder with a full daily workflow:
-/// see what's due, check it off, feel progress.
+/// Replaces the former stacked overdue/today/tomorrow daily plan layout.
+/// Users navigate by tapping day cards to see that day's tasks.
 class HomeScreen extends ConsumerStatefulWidget {
   const HomeScreen({super.key});
 
@@ -25,365 +19,51 @@ class HomeScreen extends ConsumerStatefulWidget {
 }
 
 class _HomeScreenState extends ConsumerState<HomeScreen> {
-  /// Task IDs currently animating out after completion.
-  final Set<int> _completingTaskIds = {};
+  late final CalendarStripController _stripController =
+      CalendarStripController();
 
-  void _onTaskCompleted(int taskId) {
-    setState(() {
-      _completingTaskIds.add(taskId);
-    });
-    ref.read(taskActionsProvider.notifier).completeTask(taskId);
-  }
+  /// Whether to show the floating "Heute" button.
+  /// True when the user has scrolled away from today's card.
+  bool _showTodayButton = false;
 
   @override
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context);
-    final theme = Theme.of(context);
-    final dailyPlan = ref.watch(dailyPlanProvider);
 
-    return dailyPlan.when(
-      loading: () => const Center(child: CircularProgressIndicator()),
-      error: (error, _) => Center(child: Text(error.toString())),
-      data: (state) {
-        // Clean up completing IDs that are no longer in the data
-        _completingTaskIds.removeWhere((id) =>
-            !state.overdueTasks.any((t) => t.task.id == id) &&
-            !state.todayTasks.any((t) => t.task.id == id));
-
-        return _buildDailyPlan(context, state, l10n, theme);
-      },
-    );
-  }
-
-  Widget _buildDailyPlan(
-    BuildContext context,
-    DailyPlanState state,
-    AppLocalizations l10n,
-    ThemeData theme,
-  ) {
-    // Case a: No tasks at all (user hasn't created any rooms/tasks)
-    if (state.totalTodayCount == 0 &&
-        state.tomorrowTasks.isEmpty &&
-        state.completedTodayCount == 0) {
-      return _buildNoTasksState(l10n, theme);
-    }
-
-    // Case b: All clear -- there WERE tasks today but all are done
-    if (state.overdueTasks.isEmpty &&
-        state.todayTasks.isEmpty &&
-        state.completedTodayCount > 0 &&
-        state.tomorrowTasks.isEmpty) {
-      return _buildAllClearState(state, l10n, theme);
-    }
-
-    // Case c: Nothing today, but stuff tomorrow -- show celebration + tomorrow
-    if (state.overdueTasks.isEmpty &&
-        state.todayTasks.isEmpty &&
-        state.completedTodayCount == 0 &&
-        state.tomorrowTasks.isNotEmpty) {
-      return _buildAllClearWithTomorrow(state, l10n, theme);
-    }
-
-    // Case b extended: all clear with tomorrow tasks
-    if (state.overdueTasks.isEmpty &&
-        state.todayTasks.isEmpty &&
-        state.completedTodayCount > 0 &&
-        state.tomorrowTasks.isNotEmpty) {
-      return _buildAllClearWithTomorrow(state, l10n, theme);
-    }
-
-    // Case d: Normal state -- tasks exist
-    return _buildNormalState(state, l10n, theme);
-  }
-
-  /// No tasks at all -- first-run empty state.
-  Widget _buildNoTasksState(AppLocalizations l10n, ThemeData theme) {
-    return Center(
-      child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 32),
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            Icon(
-              Icons.checklist_rounded,
-              size: 80,
-              color: theme.colorScheme.onSurface.withValues(alpha: 0.4),
-            ),
-            const SizedBox(height: 24),
-            Text(
-              l10n.dailyPlanNoTasks,
-              style: theme.textTheme.headlineSmall,
-              textAlign: TextAlign.center,
-            ),
-            const SizedBox(height: 8),
-            Text(
-              l10n.homeEmptyMessage,
-              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'),
-              child: Text(l10n.homeEmptyAction),
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
-  /// All tasks done, no tomorrow tasks -- celebration state.
-  Widget _buildAllClearState(
-    DailyPlanState state,
-    AppLocalizations l10n,
-    ThemeData theme,
-  ) {
-    return Center(
-      child: Padding(
-        padding: const EdgeInsets.symmetric(horizontal: 32),
-        child: Column(
-          mainAxisSize: MainAxisSize.min,
-          children: [
-            ProgressCard(
-              completed: state.completedTodayCount,
-              total: state.totalTodayCount,
-            ),
-            const SizedBox(height: 16),
-            Icon(
-              Icons.celebration_outlined,
-              size: 80,
-              color: theme.colorScheme.onSurface.withValues(alpha: 0.4),
-            ),
-            const SizedBox(height: 24),
-            Text(
-              l10n.dailyPlanAllClearTitle,
-              style: theme.textTheme.headlineSmall,
-              textAlign: TextAlign.center,
-            ),
-            const SizedBox(height: 8),
-            Text(
-              l10n.dailyPlanAllClearMessage,
-              style: theme.textTheme.bodyLarge?.copyWith(
-                color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
-              ),
-              textAlign: TextAlign.center,
-            ),
-          ],
-        ),
-      ),
-    );
-  }
-
-  /// All clear for today but tomorrow tasks exist.
-  Widget _buildAllClearWithTomorrow(
-    DailyPlanState state,
-    AppLocalizations l10n,
-    ThemeData theme,
-  ) {
-    return ListView(
+    return Stack(
       children: [
-        ProgressCard(
-          completed: state.completedTodayCount,
-          total: state.totalTodayCount,
+        Column(
+          children: [
+            CalendarStrip(
+              controller: _stripController,
+              onTodayVisibilityChanged: (visible) {
+                setState(() => _showTodayButton = !visible);
+              },
+            ),
+            const Expanded(child: CalendarDayList()),
+          ],
         ),
-        const SizedBox(height: 16),
-        Center(
-          child: Column(
-            children: [
-              Icon(
-                Icons.celebration_outlined,
-                size: 80,
-                color: theme.colorScheme.onSurface.withValues(alpha: 0.4),
+        if (_showTodayButton)
+          Positioned(
+            bottom: 16,
+            left: 0,
+            right: 0,
+            child: Center(
+              child: FloatingActionButton.extended(
+                onPressed: () {
+                  final now = DateTime.now();
+                  final today = DateTime(now.year, now.month, now.day);
+                  ref
+                      .read(selectedDateProvider.notifier)
+                      .selectDate(today);
+                  _stripController.scrollToToday();
+                },
+                icon: const Icon(Icons.today),
+                label: Text(l10n.calendarTodayButton),
               ),
-              const SizedBox(height: 24),
-              Text(
-                l10n.dailyPlanAllClearTitle,
-                style: theme.textTheme.headlineSmall,
-                textAlign: TextAlign.center,
-              ),
-              const SizedBox(height: 8),
-              Text(
-                l10n.dailyPlanAllClearMessage,
-                style: theme.textTheme.bodyLarge?.copyWith(
-                  color: theme.colorScheme.onSurface.withValues(alpha: 0.6),
-                ),
-                textAlign: TextAlign.center,
-              ),
-            ],
+            ),
           ),
-        ),
-        const SizedBox(height: 16),
-        _buildTomorrowSection(state, l10n, theme),
       ],
     );
   }
-
-  /// Normal state with overdue/today/tomorrow sections.
-  Widget _buildNormalState(
-    DailyPlanState state,
-    AppLocalizations l10n,
-    ThemeData theme,
-  ) {
-    return ListView(
-      children: [
-        ProgressCard(
-          completed: state.completedTodayCount,
-          total: state.totalTodayCount,
-        ),
-        // Overdue section (conditional)
-        if (state.overdueTasks.isNotEmpty) ...[
-          _buildSectionHeader(
-            l10n.dailyPlanSectionOverdue,
-            theme,
-            color: _overdueColor,
-          ),
-          ...state.overdueTasks.map(
-            (tw) => _buildAnimatedTaskRow(tw, showCheckbox: true),
-          ),
-        ],
-        // Today section
-        _buildSectionHeader(
-          l10n.dailyPlanSectionToday,
-          theme,
-          color: theme.colorScheme.primary,
-        ),
-        if (state.todayTasks.isEmpty)
-          Padding(
-            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
-            child: Text(
-              l10n.dailyPlanAllClearMessage,
-              style: theme.textTheme.bodyMedium?.copyWith(
-                color: theme.colorScheme.onSurfaceVariant,
-              ),
-            ),
-          )
-        else
-          ...state.todayTasks.map(
-            (tw) => _buildAnimatedTaskRow(tw, showCheckbox: true),
-          ),
-        // Tomorrow section (conditional, collapsed)
-        if (state.tomorrowTasks.isNotEmpty)
-          _buildTomorrowSection(state, l10n, theme),
-      ],
-    );
-  }
-
-  Widget _buildSectionHeader(
-    String title,
-    ThemeData theme, {
-    required Color color,
-  }) {
-    return Padding(
-      padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
-      child: Text(
-        title,
-        style: theme.textTheme.titleMedium?.copyWith(color: color),
-      ),
-    );
-  }
-
-  Widget _buildAnimatedTaskRow(
-    TaskWithRoom tw, {
-    required bool showCheckbox,
-  }) {
-    final isCompleting = _completingTaskIds.contains(tw.task.id);
-
-    if (isCompleting) {
-      return _CompletingTaskRow(
-        key: ValueKey('completing-${tw.task.id}'),
-        taskWithRoom: tw,
-      );
-    }
-
-    return DailyPlanTaskRow(
-      key: ValueKey('task-${tw.task.id}'),
-      taskWithRoom: tw,
-      showCheckbox: showCheckbox,
-      onCompleted: () => _onTaskCompleted(tw.task.id),
-    );
-  }
-
-  Widget _buildTomorrowSection(
-    DailyPlanState state,
-    AppLocalizations l10n,
-    ThemeData theme,
-  ) {
-    return ExpansionTile(
-      initiallyExpanded: false,
-      title: Text(
-        l10n.dailyPlanUpcomingCount(state.tomorrowTasks.length),
-        style: theme.textTheme.titleMedium,
-      ),
-      children: state.tomorrowTasks
-          .map(
-            (tw) => DailyPlanTaskRow(
-              key: ValueKey('tomorrow-${tw.task.id}'),
-              taskWithRoom: tw,
-              showCheckbox: false,
-            ),
-          )
-          .toList(),
-    );
-  }
-}
-
-/// A task row that animates to zero height on completion.
-class _CompletingTaskRow extends StatefulWidget {
-  const _CompletingTaskRow({
-    super.key,
-    required this.taskWithRoom,
-  });
-
-  final TaskWithRoom taskWithRoom;
-
-  @override
-  State<_CompletingTaskRow> createState() => _CompletingTaskRowState();
-}
-
-class _CompletingTaskRowState extends State<_CompletingTaskRow>
-    with SingleTickerProviderStateMixin {
-  late final AnimationController _controller;
-  late final Animation<double> _sizeAnimation;
-  late final Animation<Offset> _slideAnimation;
-
-  @override
-  void initState() {
-    super.initState();
-    _controller = AnimationController(
-      duration: const Duration(milliseconds: 300),
-      vsync: this,
-    );
-    _sizeAnimation = Tween<double>(begin: 1.0, end: 0.0).animate(
-      CurvedAnimation(parent: _controller, curve: Curves.easeInOut),
-    );
-    _slideAnimation = Tween<Offset>(
-      begin: Offset.zero,
-      end: const Offset(1.0, 0.0),
-    ).animate(
-      CurvedAnimation(parent: _controller, curve: Curves.easeInOut),
-    );
-    _controller.forward();
-  }
-
-  @override
-  void dispose() {
-    _controller.dispose();
-    super.dispose();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return SizeTransition(
-      sizeFactor: _sizeAnimation,
-      child: SlideTransition(
-        position: _slideAnimation,
-        child: DailyPlanTaskRow(
-          taskWithRoom: widget.taskWithRoom,
-          showCheckbox: true,
-        ),
-      ),
-    );
-  }
 }