feat(ui): 7-day daily-reward popup on home

Presentational DailyRewardSheet (7 cells, today highlighted, reward icons
from the calendar table, claim + watch-ad-2x buttons). HomeScreen becomes a
ConsumerStatefulWidget that shows it once per mount via a post-frame guard;
the 2x path grants the doubled reward only if the rewarded ad was earned,
else the base reward. Guards the throwing saveRepositoryProvider default so
a repo-less mount is a no-op.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/ui/screens/home_screen.dart

@@ -6,6 +6,7 @@ import '../../game/models/stage.dart';
 import '../../l10n/gen/app_localizations.dart';
 import '../../state/providers.dart';
 import '../widgets/banner_ad_slot.dart';
+import '../widgets/daily_reward_sheet.dart';
 import '../widgets/fade_route.dart';
 import '../widgets/pressable_scale.dart';
 import '../widgets/season_background.dart';
@@ -13,9 +14,14 @@ import 'game_screen.dart';
 import 'season_map_screen.dart';
 import 'settings_screen.dart';
 
-class HomeScreen extends ConsumerWidget {
+class HomeScreen extends ConsumerStatefulWidget {
   const HomeScreen({super.key});
 
+  @override
+  ConsumerState<HomeScreen> createState() => _HomeScreenState();
+}
+
+class _HomeScreenState extends ConsumerState<HomeScreen> {
   static const _logoColors = [
     Color(0xFFFF7EB3),
     Color(0xFFFFD166),
@@ -23,8 +29,52 @@ class HomeScreen extends ConsumerWidget {
     Color(0xFF7EDB9C),
   ];
 
+  bool _dailyChecked = false;
+
   @override
-  Widget build(BuildContext context, WidgetRef ref) {
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) => _maybeShowDailyReward());
+  }
+
+  /// Once per home mount, surface the 7-day login reward if it is claimable
+  /// today. Guards the deliberately-throwing [saveRepositoryProvider] default
+  /// so a repo-less mount (e.g. a widget test) is a no-op rather than a crash.
+  void _maybeShowDailyReward() {
+    if (_dailyChecked || !mounted) return;
+    _dailyChecked = true;
+    try {
+      ref.read(saveRepositoryProvider);
+    } catch (_) {
+      return;
+    }
+    final daily = ref.read(dailyRewardProvider);
+    if (!daily.claimable) return;
+
+    showDialog<void>(
+      context: context,
+      builder: (dialogContext) => Dialog(
+        child: DailyRewardSheet(
+          day: daily.day,
+          onClaim: (doubled) async {
+            final notifier = ref.read(dailyRewardProvider.notifier);
+            if (doubled) {
+              // Watch an ad to double; if no ad was earned the base reward is
+              // still granted so the player is never left empty-handed.
+              final earned = await ref.read(adServiceProvider).showRewarded();
+              await notifier.claim(doubled: earned);
+            } else {
+              await notifier.claim();
+            }
+            if (dialogContext.mounted) Navigator.of(dialogContext).pop();
+          },
+        ),
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context)!;
     final streak = ref.watch(streakProvider);
     final best = ref.watch(endlessBestProvider);

lib/ui/widgets/daily_reward_sheet.dart

@@ -0,0 +1,147 @@
+// lib/ui/widgets/daily_reward_sheet.dart
+import 'package:flutter/material.dart';
+
+import '../../game/daily/daily_reward.dart';
+import '../../game/models/booster.dart';
+import '../../l10n/gen/app_localizations.dart';
+
+/// Presentational 7-day login calendar. [day] is today's calendar position
+/// (1..7); past days read as claimed, the future stays locked. [onClaim] fires
+/// with `false` for a plain claim and `true` for the watch-an-ad "2×" claim.
+class DailyRewardSheet extends StatelessWidget {
+  const DailyRewardSheet({super.key, required this.day, required this.onClaim});
+
+  final int day;
+  final void Function(bool doubled) onClaim;
+
+  static const _cal = DailyRewardCalendar();
+  static const _icons = {
+    BoosterType.hammer: Icons.gavel,
+    BoosterType.shuffle: Icons.shuffle,
+    BoosterType.lineBomb: Icons.clear_all,
+  };
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context)!;
+    return Padding(
+      padding: const EdgeInsets.all(20),
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        children: [
+          Text(
+            l10n.dailyRewardTitle,
+            style: Theme.of(context).textTheme.titleLarge,
+          ),
+          const SizedBox(height: 16),
+          Wrap(
+            spacing: 8,
+            runSpacing: 8,
+            alignment: WrapAlignment.center,
+            children: [
+              for (var d = 1; d <= DailyRewardCalendar.cycle; d++)
+                _DayCell(
+                  key: ValueKey('daily_day_$d'),
+                  day: d,
+                  reward: _cal.rewardFor(d),
+                  past: d < day,
+                  today: d == day,
+                ),
+            ],
+          ),
+          const SizedBox(height: 20),
+          FilledButton(
+            key: const ValueKey('daily_claim'),
+            onPressed: () => onClaim(false),
+            child: Text(l10n.dailyClaim),
+          ),
+          const SizedBox(height: 4),
+          TextButton(
+            key: const ValueKey('daily_double'),
+            onPressed: () => onClaim(true),
+            child: Text(l10n.dailyDoubleWithAd),
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class _DayCell extends StatelessWidget {
+  const _DayCell({
+    super.key,
+    required this.day,
+    required this.reward,
+    required this.past,
+    required this.today,
+  });
+
+  final int day;
+  final Map<BoosterType, int> reward;
+  final bool past;
+  final bool today;
+
+  @override
+  Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
+    return Opacity(
+      opacity: past ? 0.45 : 1,
+      child: Container(
+        width: 66,
+        padding: const EdgeInsets.symmetric(vertical: 8, horizontal: 4),
+        decoration: BoxDecoration(
+          borderRadius: BorderRadius.circular(10),
+          color: today
+              ? scheme.primary.withValues(alpha: 0.25)
+              : Colors.white.withValues(alpha: 0.06),
+          border: today
+              ? Border.all(color: scheme.primary, width: 2)
+              : null,
+        ),
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            Text('$day', style: Theme.of(context).textTheme.labelMedium),
+            const SizedBox(height: 4),
+            Wrap(
+              spacing: 2,
+              runSpacing: 2,
+              alignment: WrapAlignment.center,
+              children: [
+                for (final entry in reward.entries)
+                  _RewardIcon(
+                    icon: DailyRewardSheet._icons[entry.key]!,
+                    count: entry.value,
+                  ),
+              ],
+            ),
+            if (past)
+              const Padding(
+                padding: EdgeInsets.only(top: 2),
+                child: Icon(Icons.check_circle,
+                    size: 14, color: Colors.greenAccent),
+              ),
+          ],
+        ),
+      ),
+    );
+  }
+}
+
+class _RewardIcon extends StatelessWidget {
+  const _RewardIcon({required this.icon, required this.count});
+
+  final IconData icon;
+  final int count;
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        Icon(icon, size: 14),
+        Text('$count', style: const TextStyle(fontSize: 11)),
+      ],
+    );
+  }
+}