feature: Added LibMDK video player backend (#162)

Co-authored-by: PartyDonut <PartyDonut@users.noreply.github.com>

lib/stubs/web/lib_mdk_web.dart

@@ -0,0 +1,75 @@
+import 'dart:async';
+
+import 'package:flutter/material.dart';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+import 'package:fladder/models/items/media_streams_model.dart';
+import 'package:fladder/models/playback/playback_model.dart';
+import 'package:fladder/wrappers/players/base_player.dart';
+import 'package:fladder/wrappers/players/player_states.dart';
+
+// This is a stub class that provides the same method signatures as the original
+// implementation, ensuring web builds compile without requiring changes elsewhere.
+class LibMDK extends BasePlayer {
+  final StreamController<PlayerState> _stateController = StreamController.broadcast();
+
+  @override
+  Stream<PlayerState> get stateStream => _stateController.stream;
+
+  @override
+  Future<void> init(Ref ref) async {}
+
+  @override
+  Future<void> dispose() async {}
+
+  @override
+  Future<void> open(String url, bool play) async {}
+
+  void setState(PlayerState state) {}
+
+  void updateState() {}
+
+  @override
+  Future<void> pause() async {}
+
+  @override
+  Future<void> play() async {}
+  @override
+  Future<void> playOrPause() async {}
+
+  @override
+  Future<void> seek(Duration position) async {}
+
+  @override
+  Future<int> setAudioTrack(AudioStreamModel? model, PlaybackModel playbackModel) async {
+    return -1;
+  }
+
+  @override
+  Future<void> setSpeed(double speed) async {}
+
+  @override
+  Future<int> setSubtitleTrack(SubStreamModel? model, PlaybackModel playbackModel) async {
+    return -1;
+  }
+
+  @override
+  Future<void> stop() async {}
+
+  @override
+  Widget? videoWidget(
+    Key key,
+    BoxFit fit,
+  ) =>
+      null;
+
+  @override
+  Widget? subtitles(bool showOverlay) => null;
+
+  @override
+  Future<void> setVolume(double volume) async {}
+
+  @override
+  Future<void> loop(bool loop) async {}
+}