first implementation finished

app/lib/features/search_browser/domain/providers.dart

@@ -0,0 +1,44 @@
+// ignore_for_file: use_setters_to_change_properties
+
+import 'package:flutter/widgets.dart';
+import 'package:kagi_bang_bang/features/search_browser/domain/entities/sheet.dart';
+import 'package:kagi_bang_bang/features/search_browser/domain/services/create_tab.dart';
+import 'package:riverpod_annotation/riverpod_annotation.dart';
+
+part 'providers.g.dart';
+
+@Riverpod()
+class OverlayDialog extends _$OverlayDialog {
+  @override
+  Widget? build() {
+    return null;
+  }
+
+  void show(Widget dialog) {
+    state = dialog;
+  }
+
+  void dismiss() {
+    state = null;
+  }
+}
+
+@Riverpod()
+class BottomSheet extends _$BottomSheet {
+  @override
+  Sheet? build() {
+    return ref.watch(
+      createTabStreamProvider.select(
+        (value) => value.valueOrNull,
+      ),
+    );
+  }
+
+  void show(Sheet sheet) {
+    state = sheet;
+  }
+
+  void dismiss() {
+    state = null;
+  }
+}