feat: make sensor and tag lists refreshable

lib/features/sensors/sensor_list_screen.dart

@@ -40,13 +40,27 @@ class SensorListScreen extends ConsumerWidget {
               error: (e, _) => Center(child: Text(e.toString())),
               data: (list) {
                 if (list.isEmpty) {
-                  return const Center(child: Text('No sensors enrolled yet'));
+                  return RefreshIndicator(
+                    onRefresh: () => ref.refresh(sensorsProvider.future),
+                    child: const CustomScrollView(
+                      physics: AlwaysScrollableScrollPhysics(),
+                      slivers: [
+                        SliverFillRemaining(
+                          child: Center(
+                              child: Text('No sensors enrolled yet')),
+                        ),
+                      ],
+                    ),
+                  );
                 }
                 final unplaced =
                     list.where((s) => !s.isPlaced).toList();
                 final placed =
                     list.where((s) => s.isPlaced).toList();
-                return ListView(
+                return RefreshIndicator(
+                  onRefresh: () => ref.refresh(sensorsProvider.future),
+                  child: ListView(
+                    physics: const AlwaysScrollableScrollPhysics(),
                     children: [
                       if (unplaced.isNotEmpty) ...[
                         _SectionHeader(
@@ -59,6 +73,7 @@ class SensorListScreen extends ConsumerWidget {
                         ...placed.map((s) => _SensorTile(sensor: s)),
                       ],
                     ],
+                  ),
                 );
               },
             ),

lib/features/tags/tag_list_screen.dart

@@ -29,15 +29,35 @@ class TagListScreen extends ConsumerWidget {
         error: (e, _) => Center(child: Text(e.toString())),
         data: (list) {
           if (list.isEmpty) {
-            return const Center(child: Text('No tags enrolled yet'));
+            return RefreshIndicator(
+              onRefresh: () {
+                ref.invalidate(roomOccupancyProvider);
+                return ref.refresh(tagsProvider.future);
+              },
+              child: const CustomScrollView(
+                physics: AlwaysScrollableScrollPhysics(),
+                slivers: [
+                  SliverFillRemaining(
+                    child: Center(child: Text('No tags enrolled yet')),
+                  ),
+                ],
+              ),
+            );
           }
-          return ListView(
+          return RefreshIndicator(
+            onRefresh: () {
+              ref.invalidate(roomOccupancyProvider);
+              return ref.refresh(tagsProvider.future);
+            },
+            child: ListView(
+              physics: const AlwaysScrollableScrollPhysics(),
               children: list
                   .map((t) => _TagTile(
                         tag: t,
                         roomId: tagRoomMap[t.tagId],
                       ))
                   .toList(),
+            ),
           );
         },
       ),