feat(account): add source to follow page

- Implemented source selection
- Added follow/unfollow logic
- Displays available sources

Author: fulleni

lib/account/view/add_source_to_follow_page.dart

@@ -0,0 +1,95 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:ht_main/account/bloc/account_bloc.dart';
+import 'package:ht_main/headlines-feed/bloc/sources_filter_bloc.dart';
+import 'package:ht_main/l10n/l10n.dart';
+import 'package:ht_main/shared/constants/app_spacing.dart';
+import 'package:ht_main/shared/widgets/widgets.dart';
+import 'package:ht_shared/ht_shared.dart';
+import 'package:ht_data_repository/ht_data_repository.dart';
+
+/// {@template add_source_to_follow_page}
+/// A page that allows users to browse and select sources to follow.
+/// {@endtemplate}
+class AddSourceToFollowPage extends StatelessWidget {
+  /// {@macro add_source_to_follow_page}
+  const AddSourceToFollowPage({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = context.l10n;
+    return BlocProvider(
+      create: (context) => SourcesFilterBloc(
+        sourcesRepository: context.read<HtDataRepository<Source>>(),
+        countriesRepository: context.read<HtDataRepository<Country>>(),
+      )..add(const LoadSourceFilterData()), // Use correct event
+      child: Scaffold(
+        appBar: AppBar(
+          title: Text(l10n.addSourcesPageTitle),
+        ),
+        body: BlocBuilder<SourcesFilterBloc, SourcesFilterState>(
+          builder: (context, sourcesState) {
+            if (sourcesState.dataLoadingStatus == SourceFilterDataLoadingStatus.loading || sourcesState.dataLoadingStatus == SourceFilterDataLoadingStatus.initial) {
+              return const Center(child: CircularProgressIndicator());
+            }
+            if (sourcesState.dataLoadingStatus == SourceFilterDataLoadingStatus.failure) {
+              return FailureStateWidget(
+                message: sourcesState.errorMessage ?? l10n.sourceFilterError,
+                onRetry: () => context
+                    .read<SourcesFilterBloc>()
+                    .add(const LoadSourceFilterData()), // Use correct event
+              );
+            }
+            // Use allAvailableSources to display all sources for selection
+            if (sourcesState.allAvailableSources.isEmpty) {
+              return FailureStateWidget(
+                message: l10n.sourceFilterEmptyHeadline, // Re-use
+              );
+            }
+
+            return BlocBuilder<AccountBloc, AccountState>(
+              builder: (context, accountState) {
+                final followedSources =
+                    accountState.preferences?.followedSources ?? [];
+
+                return ListView.builder(
+                  padding: const EdgeInsets.all(AppSpacing.md),
+                  itemCount: sourcesState.allAvailableSources.length, // Use allAvailableSources
+                  itemBuilder: (context, index) {
+                    final source = sourcesState.allAvailableSources[index]; // Use allAvailableSources
+                    final isFollowed =
+                        followedSources.any((fs) => fs.id == source.id);
+
+                    return Card(
+                      margin: const EdgeInsets.only(bottom: AppSpacing.sm),
+                      child: ListTile(
+                        // Consider adding source.iconUrl if available
+                        title: Text(source.name),
+                        trailing: IconButton(
+                          icon: isFollowed
+                              ? Icon(
+                                  Icons.check_circle,
+                                  color: Theme.of(context).colorScheme.primary,
+                                )
+                              : const Icon(Icons.add_circle_outline),
+                          tooltip: isFollowed
+                              ? l10n.unfollowSourceTooltip(source.name)
+                              : l10n.followSourceTooltip(source.name), // New
+                          onPressed: () {
+                            context.read<AccountBloc>().add(
+                                  AccountFollowSourceToggled(source: source),
+                                );
+                          },
+                        ),
+                      ),
+                    );
+                  },
+                );
+              },
+            );
+          },
+        ),
+      ),
+    );
+  }
+}