feat: integrate Clock In functionality with Firebase support and refactor attendance management

apps/mobile/packages/domain/lib/src/entities/clock_in/attendance_status.dart

@@ -0,0 +1,19 @@
+import 'package:equatable/equatable.dart';
+
+/// Simple entity to hold attendance state
+class AttendanceStatus extends Equatable {
+  final bool isCheckedIn;
+  final DateTime? checkInTime;
+  final DateTime? checkOutTime;
+  final String? activeShiftId;
+
+  const AttendanceStatus({
+    this.isCheckedIn = false,
+    this.checkInTime,
+    this.checkOutTime,
+    this.activeShiftId,
+  });
+
+  @override
+  List<Object?> get props => [isCheckedIn, checkInTime, checkOutTime, activeShiftId];
+}