feat: shuffle play button on media detail screen

lib/utils/shuffle_play_helper.dart

@@ -0,0 +1,83 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import '../models/plex_metadata.dart';
+import '../providers/playback_state_provider.dart';
+import '../utils/provider_extensions.dart';
+import '../utils/video_player_navigation.dart';
+
+/// Handle shuffle play action for shows and seasons
+///
+/// Fetches all unwatched episodes, shuffles them, and starts playback
+/// from the first shuffled episode. The shuffle queue is stored in the
+/// PlaybackStateProvider for continuous shuffle playback.
+Future<void> handleShufflePlay(
+  BuildContext context,
+  PlexMetadata metadata,
+) async {
+  final client = context.client;
+  if (client == null) return;
+
+  final playbackState = context.read<PlaybackStateProvider>();
+  final itemType = metadata.type.toLowerCase();
+
+  try {
+    // Show loading indicator
+    if (context.mounted) {
+      showDialog(
+        context: context,
+        barrierDismissible: false,
+        builder: (context) =>
+            const Center(child: CircularProgressIndicator()),
+      );
+    }
+
+    // Get unwatched episodes based on type
+    List<PlexMetadata> episodes;
+    if (itemType == 'show') {
+      episodes = await client.getAllUnwatchedEpisodes(
+        metadata.ratingKey,
+      );
+    } else {
+      // season
+      episodes = await client.getUnwatchedEpisodesInSeason(
+        metadata.ratingKey,
+      );
+    }
+
+    // Close loading indicator
+    if (context.mounted) {
+      Navigator.pop(context);
+    }
+
+    if (episodes.isEmpty) {
+      if (context.mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          const SnackBar(content: Text('No unwatched episodes found')),
+        );
+      }
+      return;
+    }
+
+    // Shuffle the episodes
+    episodes.shuffle();
+
+    // Store shuffle queue in provider
+    playbackState.setShuffleQueue(episodes, metadata.ratingKey);
+
+    // Navigate to first episode
+    if (context.mounted) {
+      await navigateToVideoPlayer(context, metadata: episodes.first);
+    }
+  } catch (e) {
+    // Close loading indicator if it's still open
+    if (context.mounted && Navigator.canPop(context)) {
+      Navigator.pop(context);
+    }
+
+    if (context.mounted) {
+      ScaffoldMessenger.of(context).showSnackBar(
+        SnackBar(content: Text('Error starting shuffle play: $e')),
+      );
+    }
+  }
+}