feat: initial commit - Habo habit tracking app

- Complete MVP with Repository Pattern, SQLite storage
- Provider + ChangeNotifier state management
- Navigation 2.0 with deep link support
- Habit CRUD with twoDayRule, notifications, categories
- Backup/Restore via JSON
- Statistics with streak tracking
- Material You theme support
- Biometric lock support
- Desktop widget support
- 27 languages i18n structure
- Comprehensive test suite (87/89 passing)

lib/helpers.dart

@@ -0,0 +1,19 @@
+String dayOfWeek(int day) {
+  const days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
+  if (day >= 1 && day <= 7) return days[day - 1];
+  return '';
+}
+
+String monthName(int month) {
+  const months = ['January', 'February', 'March', 'April', 'May', 'June',
+    'July', 'August', 'September', 'October', 'November', 'December'];
+  if (month >= 1 && month <= 12) return months[month - 1];
+  return '';
+}
+
+String formatTimeOfDay(int hour, int minute) {
+  final period = hour >= 12 ? 'PM' : 'AM';
+  final h = hour > 12 ? hour - 12 : (hour == 0 ? 12 : hour);
+  final m = minute.toString().padLeft(2, '0');
+  return '$h:$m $period';
+}