Enhance AppSettings and RentController to manage not-occupied months, add lifetime summary to SettingsScreen, and update tests for compatibility

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

lib/screens/home_screen.dart

@@ -34,6 +34,12 @@ class HomeScreen extends StatelessWidget {
                 selected: current == PaymentStatus.notPaid,
                 onTap: () => Navigator.of(context).pop(PaymentStatus.notPaid),
               ),
+              ListTile(
+                title: const Text('Not occupied'),
+                selected: current == PaymentStatus.notOccupied,
+                onTap: () =>
+                    Navigator.of(context).pop(PaymentStatus.notOccupied),
+              ),
               ListTile(
                 title: const Text('Pending'),
                 selected: current == PaymentStatus.pending,
@@ -91,20 +97,6 @@ class HomeScreen extends StatelessWidget {
     RentController controller,
     RentTableRow row,
   ) async {
-    if (row.status == PaymentStatus.notOccupied) {
-      if (!context.mounted) {
-        return;
-      }
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(
-          content: Text(
-            'Use Settings -> Unit occupied to manage not-occupied months.',
-          ),
-        ),
-      );
-      return;
-    }
-
     final nextStatus = await _showStatusPicker(context, row.status);
     if (!context.mounted) {
       return;
@@ -114,8 +106,9 @@ class HomeScreen extends StatelessWidget {
     }
 
     double? paidUsd;
-    if (nextStatus == PaymentStatus.onTime ||
-        nextStatus == PaymentStatus.late) {
+    if (nextStatus == PaymentStatus.onTime) {
+      paidUsd = controller.settings.rentUsd;
+    } else if (nextStatus == PaymentStatus.late) {
       paidUsd = await _showPaidUsdDialog(
         context,
         initialValue: row.usdAmount ?? controller.settings.rentUsd,
@@ -186,8 +179,11 @@ class HomeScreen extends StatelessWidget {
                     children: <Widget>[
                       _YearSwitcher(
                         year: controller.selectedYear,
-                        onPrevious: () =>
-                            controller.selectYear(controller.selectedYear - 1),
+                        onPrevious: controller.canSelectPreviousYear
+                            ? () => controller.selectYear(
+                                controller.selectedYear - 1,
+                              )
+                            : null,
                         onNext: controller.selectedYear < DateTime.now().year
                             ? () => controller.selectYear(
                                 controller.selectedYear + 1,
@@ -282,7 +278,7 @@ class HomeScreen extends StatelessWidget {
                         'Total: ${usdCurrency.format(totalUsd)} | ${sekCurrency.format(totalSek)}',
                         style: Theme.of(context).textTheme.titleMedium,
                       ),
-                      const SizedBox(height: 12),
+
                       FilledButton.icon(
                         onPressed: () async {
                           await controller.markCurrentMonthPaidManually();
@@ -337,7 +333,7 @@ class _YearSwitcher extends StatelessWidget {
   });
 
   final int year;
-  final VoidCallback onPrevious;
+  final VoidCallback? onPrevious;
   final VoidCallback? onNext;
 
   @override