feat: Add settings to control play button visibility on home shelves

This commit introduces new functionality to customize the visibility of the
play button on home page shelves.

Key changes:

- Added `HomePageSettings` to `AppSettings` to store your preferences:
    - `showPlayButtonOnContinueShelves`: Controls visibility on "Continue Listening" and "Continue Series" shelves (default: true).
    - `showPlayButtonOnAllShelves`: Controls visibility on other shelves (default: false).
- Modified `BookHomeShelf` to respect these settings when rendering books.
- Created a new "Home Page Settings" page under "Appearance" in App Settings, allowing you to toggle these two options.
- Added comprehensive unit and widget tests to cover the new settings model, the conditional logic in `BookHomeShelf`, and the functionality of the new settings page.

test/widgets/shelves/book_shelf_test.dart

@@ -0,0 +1,169 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+import 'package:shelfsdk/audiobookshelf_api.dart';
+import 'package:vaani/api/image_provider.dart';
+import 'package:vaani/settings/models/app_settings.dart';
+import 'package:vaani/settings/app_settings_provider.dart';
+import 'package:vaani/shared/widgets/shelves/book_shelf.dart';
+
+import 'book_shelf_test.mocks.dart';
+
+// Mocks
+@GenerateNiceMocks([
+  MockSpec<LibraryItem>(),
+  MockSpec<Media>(),
+  MockSpec<BookMinified>(),
+  MockSpec<BookMetadataMinified>(),
+  MockSpec<LibraryItemShelf>(),
+  MockSpec<CoverImageNotifier>(),
+])
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  // Helper function to create a mock LibraryItem
+  MockLibraryItem _createMockLibraryItem(String id) {
+    final mockItem = MockLibraryItem();
+    final mockMedia = MockMedia();
+    final mockBookMinified = MockBookMinified();
+    final mockBookMetadataMinified = MockBookMetadataMinified();
+
+    when(mockItem.id).thenReturn(id);
+    when(mockItem.mediaType).thenReturn(MediaType.book);
+    when(mockItem.media).thenReturn(mockMedia);
+    when(mockMedia.asBookMinified).thenReturn(mockBookMinified);
+    when(mockBookMinified.metadata).thenReturn(mockBookMetadataMinified);
+    when(mockBookMetadataMinified.title).thenReturn('Test Book Title');
+    when(mockBookMetadataMinified.authorName).thenReturn('Test Author');
+    return mockItem;
+  }
+
+  // Helper function to create a mock LibraryItemShelf
+  MockLibraryItemShelf _createMockLibraryItemShelf(List<LibraryItem> items) {
+    final mockShelf = MockLibraryItemShelf();
+    when(mockShelf.id).thenReturn('test-shelf-id');
+    when(mockShelf.entities).thenReturn(items);
+    return mockShelf;
+  }
+
+  // Helper function to pump BookHomeShelf with specific settings
+  Future<void> pumpBookHomeShelf({
+    required WidgetTester tester,
+    required String title,
+    required LibraryItemShelf shelf,
+    required AppSettings appSettings,
+  }) async {
+    final mockCoverImageNotifier = MockCoverImageNotifier();
+    when(mockCoverImageNotifier.build(any)).thenAnswer((_) => Uint8List(0));
+    when(mockCoverImageNotifier.future).thenAnswer((_) async => Uint8List(0));
+
+
+    await tester.pumpWidget(
+      ProviderScope(
+        overrides: [
+          appSettingsProvider.overrideWithValue(
+            AppSettingsNotifier(appSettings),
+          ),
+          // Mock the coverImageProvider to avoid network calls or file system access
+          coverImageProvider(any).overrideWith((ref, id) => mockCoverImageNotifier),
+        ],
+        child: MaterialApp(
+          home: Scaffold(
+            body: BookHomeShelf(
+              title: title,
+              shelf: shelf,
+            ),
+          ),
+        ),
+      ),
+    );
+    await tester.pumpAndSettle(); // Let animations and futures settle
+  }
+
+  // Function to find BookOnShelf and check its showPlayButton property
+  bool getShowPlayButtonForBookOnShelf(WidgetTester tester, String itemId) {
+    final bookOnShelfFinder = find.byWidgetPredicate(
+        (widget) => widget is BookOnShelf && widget.item.id == itemId);
+    expect(bookOnShelfFinder, findsOneWidget);
+    final bookOnShelfWidget = tester.widget<BookOnShelf>(bookOnShelfFinder);
+    return bookOnShelfWidget.showPlayButton;
+  }
+
+  group('BookHomeShelf Play Button Visibility', () {
+    late MockLibraryItem mockItem1;
+    late MockLibraryItemShelf mockShelf;
+
+    setUp(() {
+      mockItem1 = _createMockLibraryItem('item1');
+      mockShelf = _createMockLibraryItemShelf([mockItem1]);
+    });
+
+    testWidgets('Continue Shelves - Default: showPlayButton should be true',
+        (WidgetTester tester) async {
+      const appSettings = AppSettings(); // Default settings
+
+      await pumpBookHomeShelf(
+        tester: tester,
+        title: 'Continue Listening',
+        shelf: mockShelf,
+        appSettings: appSettings,
+      );
+
+      expect(getShowPlayButtonForBookOnShelf(tester, 'item1'), isTrue);
+    });
+
+    testWidgets('Continue Shelves - Hidden: showPlayButton should be false',
+        (WidgetTester tester) async {
+      const appSettings = AppSettings(
+        homePageSettings: HomePageSettings(
+          showPlayButtonOnContinueShelves: false,
+          showPlayButtonOnAllShelves: false, // Keep others default
+        ),
+      );
+
+      await pumpBookHomeShelf(
+        tester: tester,
+        title: 'Continue Series', // Another continue shelf title
+        shelf: mockShelf,
+        appSettings: appSettings,
+      );
+
+      expect(getShowPlayButtonForBookOnShelf(tester, 'item1'), isFalse);
+    });
+
+    testWidgets('Other Shelves - Default: showPlayButton should be false',
+        (WidgetTester tester) async {
+      const appSettings = AppSettings(); // Default settings
+
+      await pumpBookHomeShelf(
+        tester: tester,
+        title: 'Discover',
+        shelf: mockShelf,
+        appSettings: appSettings,
+      );
+
+      expect(getShowPlayButtonForBookOnShelf(tester, 'item1'), isFalse);
+    });
+
+    testWidgets('Other Shelves - Shown: showPlayButton should be true',
+        (WidgetTester tester) async {
+      const appSettings = AppSettings(
+        homePageSettings: HomePageSettings(
+          showPlayButtonOnContinueShelves: true, // Keep others default
+          showPlayButtonOnAllShelves: true,
+        ),
+      );
+
+      await pumpBookHomeShelf(
+        tester: tester,
+        title: 'New Releases',
+        shelf: mockShelf,
+        appSettings: appSettings,
+      );
+
+      expect(getShowPlayButtonForBookOnShelf(tester, 'item1'), isTrue);
+    });
+  });
+}