feat(notif): Swipe to delete notifs on map screen

lib/widgets/reminder_widgets.dart

@@ -207,11 +207,55 @@ class _ReminderWidgetsState extends State<ReminderWidgets> {
               ),
             );
             children.addAll(
+              // the dismissible widgets that show each reminder, swiping left deletes the reminder
               reminders.map(
-                (r) => ReminderWidget(
-                  rtid: r.rtid,
-                  stopName: getStopNameFromID(r.stpid),
-                  eta: r.eta,
+                (r) => Dismissible(
+                  key: Key('${r.stpid}|${r.rtid}'),
+                  direction: DismissDirection.endToStart,
+                  // the red background with the trash/delete icon that shows when swiping
+                  background: Container(
+                    color: Colors.red, // red background for delete action
+                    alignment: Alignment.centerRight,
+                    padding: EdgeInsets.only(right: 20.0),
+                    child: Icon(Icons.delete, color: Colors.white), // white trash icon
+                  ),
+                  // when the user swipes enough to dismiss
+                  // try to remove the reminder from the service
+                  // if it fails put the widget back
+                  confirmDismiss: (direction) async {
+                    try {
+                      await IncomingBusReminderService.removeReminder(
+                        r.stpid,
+                        r.rtid,
+                      );
+                      return true;
+                    } catch (e) {
+                      if (kDebugMode) {
+                        print('Failed to remove reminder: $e');
+                      }
+                      return false;
+                    }
+                  },
+                  // if the reminder was successfully removed from the service
+                  // also remove it from the local list so the widget disappears immediately
+                  onDismissed: (_) {
+                    // Remove from local list immediately so the dismissed
+                    // widget leaves the tree before the async refresh.
+                    setState(() {
+                      reminders.removeWhere(
+                        (x) => x.stpid == r.stpid && x.rtid == r.rtid,
+                      );
+                    });
+                    _resetDataFuture();
+                  },
+                  // the actual reminder widget
+                  child: ReminderWidget(
+                    stpid: r.stpid,
+                    rtid: r.rtid,
+                    stopName: getStopNameFromID(r.stpid),
+                    eta: r.eta,
+                    onDismissed: _resetDataFuture,
+                  ),
                 ),
               ),
             );
@@ -231,14 +275,18 @@ class _ReminderWidgetsState extends State<ReminderWidgets> {
 class ReminderWidget extends StatelessWidget {
   const ReminderWidget({
     super.key,
+    required this.stpid,
     required this.rtid,
     required this.stopName,
     required this.eta,
+    this.onDismissed,
   });
 
+  final String stpid;
   final String rtid;
   final String stopName;
   final int? eta;
+  final VoidCallback? onDismissed; // called when the reminder is dismissed
 
   @override
   Widget build(BuildContext context) {