feat: rooms list with real Matrix data, MXC avatars and unread badges

lib/features/rooms/rooms_provider.dart

@@ -0,0 +1,25 @@
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:matrix/matrix.dart';
+import 'package:pyramid/core/matrix_client.dart';
+
+final roomListProvider = StreamProvider<List<Room>>((ref) async* {
+  final client = await ref.watch(matrixClientProvider.future);
+
+  yield _sortedRooms(client);
+
+  await for (final _ in client.onSync.stream) {
+    yield _sortedRooms(client);
+  }
+});
+
+List<Room> _sortedRooms(Client client) {
+  final rooms = client.rooms
+      .where((r) => !r.isSpace)
+      .toList()
+    ..sort((a, b) {
+      final aTime = a.lastEvent?.originServerTs ?? DateTime(0);
+      final bTime = b.lastEvent?.originServerTs ?? DateTime(0);
+      return bTime.compareTo(aTime);
+    });
+  return rooms;
+}