♻️ Refactored publisher subscription

lib/pods/post/post_subscriptions.dart

@@ -0,0 +1,16 @@
+import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:island/models/post.dart';
+import 'package:island/pods/network.dart';
+
+final subscriptionsProvider = FutureProvider<List<SnPublisherSubscription>>((
+  ref,
+) async {
+  final client = ref.read(apiClientProvider);
+
+  final response = await client.get('/sphere/subscriptions');
+
+  return response.data
+      .map((json) => SnPublisherSubscription.fromJson(json))
+      .cast<SnPublisherSubscription>()
+      .toList();
+});