fix: cross-device watch progress sync

close #240

lib/screens/discover_screen.dart

@@ -1,4 +1,6 @@
 import 'dart:async';
+import 'dart:io' show Platform;
+
 import 'package:flutter/material.dart';
 import 'package:plezy/widgets/app_icon.dart';
 import 'package:material_symbols_icons/symbols.dart';
@@ -44,7 +46,7 @@ class DiscoverScreen extends StatefulWidget {
 }
 
 class _DiscoverScreenState extends State<DiscoverScreen>
-    with Refreshable, FullRefreshable, ItemUpdatable, WatchStateAware, SingleTickerProviderStateMixin {
+    with Refreshable, FullRefreshable, ItemUpdatable, WatchStateAware, SingleTickerProviderStateMixin, WidgetsBindingObserver {
   static const Duration _heroAutoScrollDuration = Duration(seconds: 8);
 
   @override
@@ -179,6 +181,7 @@ class _DiscoverScreenState extends State<DiscoverScreen>
   @override
   void initState() {
     super.initState();
+    WidgetsBinding.instance.addObserver(this);
     _indicatorAnimationController = AnimationController(vsync: this, duration: _heroAutoScrollDuration);
     _heroFocusNode = FocusNode(debugLabel: 'hero_section');
     _refreshButtonFocusNode = FocusNode(debugLabel: 'refresh_button');
@@ -376,6 +379,7 @@ class _DiscoverScreenState extends State<DiscoverScreen>
 
   @override
   void dispose() {
+    WidgetsBinding.instance.removeObserver(this);
     _autoScrollTimer?.cancel();
     _heroController.dispose();
     _scrollController.dispose();
@@ -390,6 +394,16 @@ class _DiscoverScreenState extends State<DiscoverScreen>
     super.dispose();
   }
 
+  @override
+  void didChangeAppLifecycleState(AppLifecycleState state) {
+    // Refresh continue watching when app resumes on mobile platforms
+    // Skip on desktop to avoid excessive refreshes from window focus changes
+    if (state == AppLifecycleState.resumed && (Platform.isIOS || Platform.isAndroid)) {
+      appLogger.d('App resumed on mobile - refreshing continue watching');
+      _refreshContinueWatching();
+    }
+  }
+
   void _startAutoScroll() {
     if (_isAutoScrollPaused) return;
 

lib/services/offline_watch_sync_service.dart

@@ -1,3 +1,5 @@
+import 'dart:io' show Platform;
+
 import 'package:flutter/foundation.dart';
 
 import '../database/app_database.dart';
@@ -31,8 +33,15 @@ class OfflineWatchSyncService extends ChangeNotifier {
   /// Watch threshold - mark as watched when progress exceeds this percentage
   static const double watchedThreshold = 0.90;
 
-  /// Minimum interval between syncs (10 minutes)
-  static const Duration minSyncInterval = Duration(minutes: 10);
+  /// Minimum interval between syncs.
+  /// Mobile: no throttle (always sync on resume for cross-device updates)
+  /// Desktop: 2 minutes (reduced from 10 min to handle tab-switching better)
+  static Duration get minSyncInterval {
+    if (Platform.isIOS || Platform.isAndroid) {
+      return Duration.zero;
+    }
+    return const Duration(minutes: 2);
+  }
 
   /// Maximum sync attempts before giving up on an item
   static const int maxSyncAttempts = 5;
@@ -107,11 +116,14 @@ class OfflineWatchSyncService extends ChangeNotifier {
     }
   }
 
-  /// Called when app becomes active - syncs if interval has passed.
+  /// Called when app becomes active - syncs for cross-device updates.
+  /// On mobile, always syncs immediately (device-switching scenario).
+  /// On desktop, respects the throttle interval.
   void onAppResumed() {
     if (_offlineModeProvider?.isOffline != true) {
-      appLogger.d('App resumed - checking if sync needed');
-      _performBidirectionalSync();
+      final isMobile = Platform.isIOS || Platform.isAndroid;
+      appLogger.d('App resumed - ${isMobile ? "forcing" : "checking"} sync');
+      _performBidirectionalSync(force: isMobile);
     }
   }
 

lib/services/plex_client.dart

@@ -357,7 +357,13 @@ class PlexClient {
   /// Uses cache when offline or as fallback on network error
   /// Note: OnDeck data is not relevant for offline mode
   /// Always fetches with chapters/markers but caches at base endpoint
-  Future<Map<String, dynamic>> getMetadataWithImagesAndOnDeck(String ratingKey) async {
+  ///
+  /// When [forceRefresh] is true, bypasses cache to get fresh OnDeck data.
+  /// Use this when cross-device sync is needed (e.g., after app resume).
+  Future<Map<String, dynamic>> getMetadataWithImagesAndOnDeck(
+    String ratingKey, {
+    bool forceRefresh = false,
+  }) async {
     // Cache key is always the base endpoint (no query params)
     final cacheKey = '/library/metadata/$ratingKey';
 
@@ -398,6 +404,7 @@ class PlexClient {
 
             return {'metadata': metadata, 'onDeckEpisode': onDeckEpisode};
           },
+          forceRefresh: forceRefresh,
         ) ??
         {'metadata': null, 'onDeckEpisode': null};
   }
@@ -470,12 +477,17 @@ class PlexClient {
   /// 3. If network succeeds and cacheResponse is true, cache the response
   /// 4. If network fails, fall back to cached data
   /// 5. If no cached data available, rethrow the network error
+  /// Fetch data with cache fallback for offline mode and network errors.
+  ///
+  /// When [forceRefresh] is true, skips reading from cache (still writes to cache).
+  /// Use this to get fresh data when cross-device sync is needed.
   Future<T?> _fetchWithCacheFallback<T>({
     required String cacheKey,
     required Future<Response> Function() networkCall,
     required T? Function(dynamic cachedData) parseCache,
     required T? Function(Response response) parseResponse,
     bool cacheResponse = true,
+    bool forceRefresh = false,
   }) async {
     if (_offlineMode) {
       final cached = await _cache.get(serverId, cacheKey);
@@ -489,6 +501,7 @@ class PlexClient {
       }
       return parseResponse(response);
     } catch (e) {
+      // On forceRefresh, still try cache as last resort on network error
       appLogger.w('Network request failed for $cacheKey, trying cache', error: e);
       final cached = await _cache.get(serverId, cacheKey);
       if (cached != null) return parseCache(cached);