chore: dedupe resolution display labels and fold single-use helpers

Two private formatters mapped the canonical server resolution label to
display text (media_quality_labels, media_version) with edge-case
drift, and several single-consumer helpers added indirection without
callers:

- add shared resolutionDisplayLabel in resolution_label.dart and
  migrate MediaVersion.displayLabel and the quality-label builder to it
- drop the resolutionLabelFromHeight compat re-export from
  jellyfin_mappers (no remaining consumers) and its stale doc note
- delete TraktCatalogSource.membershipKeysFor, byte-identical to the
  CatalogWatchlistMachinery default
- derive the rating sheet backend label from
  MediaBrowserDialect.productName instead of a hardcoded switch
- inline EndpointFailoverManager into failover_http_client.dart, its
  only importer, and remove endpoint_failover_interceptor.dart

lib/media/media_version.dart

@@ -4,6 +4,7 @@ import '../i18n/strings.g.dart';
 import '../utils/codec_utils.dart';
 import '../utils/formatters.dart';
 import '../utils/json_utils.dart';
+import '../utils/resolution_label.dart';
 import 'media_part.dart';
 
 part 'media_version.g.dart';
@@ -14,14 +15,6 @@ int? bitrateKbpsFromBps(int? bps) {
   return (bps / 1000).round();
 }
 
-final _numericVideoResolution = RegExp(r'^\d+$');
-
-/// Plex may return numeric heights (`1080`) or named resolution labels (`sd`, `4k`).
-String _videoResolutionDisplayLabel(String resolution) {
-  final value = resolution.trim();
-  return _numericVideoResolution.hasMatch(value) ? '${value}p' : value.toUpperCase();
-}
-
 /// A single media variant available for an item — represents one quality level
 /// or transcode profile of the underlying file. An item with multiple versions
 /// (e.g. 4K + 1080p re-encode) exposes one [MediaVersion] per option.
@@ -95,7 +88,7 @@ class MediaVersion {
     final parts = <String>[];
 
     if (videoResolution != null && videoResolution!.isNotEmpty) {
-      parts.add(_videoResolutionDisplayLabel(videoResolution!));
+      parts.add(resolutionDisplayLabel(videoResolution!));
     } else if (height != null) {
       parts.add('${height}p');
     }

lib/services/catalog/trakt_catalog_source.dart

@@ -242,11 +242,6 @@ class TraktCatalogSource with CatalogWatchlistMachinery implements CatalogSource
     add ? await _client.addToWatchlist(body) : await _client.removeFromWatchlist(body);
   }
 
-  @override
-  List<String> membershipKeysFor(MediaKind kind, CatalogItemIds ids) => [
-    for (final key in ids.allKeys) '${kind.id}/$key',
-  ];
-
   List<CatalogItem> _fromEntries(List<TraktCatalogEntry> entries, {MediaKind? kind}) => [
     for (final entry in entries)
       if (entry.media != null && _entryKind(entry, kind) != null && entry.media!.ids.hasAny)

lib/services/jellyfin_mappers.dart

@@ -16,10 +16,6 @@ import '../utils/resolution_label.dart';
 import 'file_info_parser.dart';
 import 'jellyfin_display_metadata.dart';
 
-// Re-export so existing callers that pulled `resolutionLabelFromHeight`
-// from this file keep compiling without a bulk import rewrite.
-export '../utils/resolution_label.dart' show resolutionLabelFromHeight;
-
 Map<String, dynamic>? jellyfinFirstVideoStream(Object? streams) {
   if (streams is! List) return null;
   for (final stream in streams) {

lib/utils/endpoint_failover_interceptor.dart

@@ -1,69 +0,0 @@
-import '../utils/app_logger.dart';
-
-/// Maintains the list of endpoints we can cycle through when one fails.
-class EndpointFailoverManager {
-  EndpointFailoverManager(List<String> urls) {
-    _setEndpoints(urls);
-  }
-
-  late List<String> _endpoints;
-  int _currentIndex = 0;
-
-  /// Incremented every time the active endpoint changes. Requests stamped with
-  /// an older generation should not trigger additional failover cascades.
-  int _generation = 0;
-  int get generation => _generation;
-
-  List<String> get endpoints => List.unmodifiable(_endpoints);
-
-  String get current => _endpoints[_currentIndex];
-
-  bool get hasFallback => _currentIndex < _endpoints.length - 1;
-
-  /// Move to the next endpoint, returning its URL or null if exhausted.
-  String? moveToNext() {
-    if (!hasFallback) return null;
-    _currentIndex++;
-    _generation++;
-    return _endpoints[_currentIndex];
-  }
-
-  /// Reset back to the first (preferred) endpoint. Called when all endpoints
-  /// are exhausted so the next failure cycle starts from the best candidate.
-  String? resetToFirst() {
-    if (_currentIndex != 0) {
-      _currentIndex = 0;
-      _generation++;
-      appLogger.d('Failover endpoint list reset to first candidate');
-      return _endpoints[_currentIndex];
-    }
-    return null;
-  }
-
-  /// Replace the endpoint list and optionally set the active endpoint.
-  void reset(List<String> urls, {String? currentBaseUrl}) {
-    _setEndpoints(urls);
-    if (currentBaseUrl != null) {
-      final index = _endpoints.indexOf(currentBaseUrl);
-      _currentIndex = index >= 0 ? index : 0;
-    } else {
-      _currentIndex = 0;
-    }
-    _generation++;
-  }
-
-  void _setEndpoints(List<String> urls) {
-    final sanitized = <String>[];
-    final seen = <String>{};
-    for (final url in urls) {
-      if (url.isEmpty || seen.contains(url)) continue;
-      seen.add(url);
-      sanitized.add(url);
-    }
-    if (sanitized.isEmpty) {
-      throw ArgumentError('At least one endpoint is required');
-    }
-    _endpoints = sanitized;
-    _currentIndex = _currentIndex.clamp(0, _endpoints.length - 1);
-  }
-}

lib/utils/failover_http_client.dart

@@ -1,4 +1,3 @@
-import 'endpoint_failover_interceptor.dart';
 import 'app_logger.dart';
 import 'media_server_http_client.dart';
 import '../exceptions/media_server_exceptions.dart';
@@ -246,3 +245,71 @@ class FailoverHttpClient extends MediaServerHttpClient {
     }
   }
 }
+
+/// Maintains the list of endpoints we can cycle through when one fails.
+class EndpointFailoverManager {
+  EndpointFailoverManager(List<String> urls) {
+    _setEndpoints(urls);
+  }
+
+  late List<String> _endpoints;
+  int _currentIndex = 0;
+
+  /// Incremented every time the active endpoint changes. Requests stamped with
+  /// an older generation should not trigger additional failover cascades.
+  int _generation = 0;
+  int get generation => _generation;
+
+  List<String> get endpoints => List.unmodifiable(_endpoints);
+
+  String get current => _endpoints[_currentIndex];
+
+  bool get hasFallback => _currentIndex < _endpoints.length - 1;
+
+  /// Move to the next endpoint, returning its URL or null if exhausted.
+  String? moveToNext() {
+    if (!hasFallback) return null;
+    _currentIndex++;
+    _generation++;
+    return _endpoints[_currentIndex];
+  }
+
+  /// Reset back to the first (preferred) endpoint. Called when all endpoints
+  /// are exhausted so the next failure cycle starts from the best candidate.
+  String? resetToFirst() {
+    if (_currentIndex != 0) {
+      _currentIndex = 0;
+      _generation++;
+      appLogger.d('Failover endpoint list reset to first candidate');
+      return _endpoints[_currentIndex];
+    }
+    return null;
+  }
+
+  /// Replace the endpoint list and optionally set the active endpoint.
+  void reset(List<String> urls, {String? currentBaseUrl}) {
+    _setEndpoints(urls);
+    if (currentBaseUrl != null) {
+      final index = _endpoints.indexOf(currentBaseUrl);
+      _currentIndex = index >= 0 ? index : 0;
+    } else {
+      _currentIndex = 0;
+    }
+    _generation++;
+  }
+
+  void _setEndpoints(List<String> urls) {
+    final sanitized = <String>[];
+    final seen = <String>{};
+    for (final url in urls) {
+      if (url.isEmpty || seen.contains(url)) continue;
+      seen.add(url);
+      sanitized.add(url);
+    }
+    if (sanitized.isEmpty) {
+      throw ArgumentError('At least one endpoint is required');
+    }
+    _endpoints = sanitized;
+    _currentIndex = _currentIndex.clamp(0, _endpoints.length - 1);
+  }
+}

lib/utils/media_quality_labels.dart

@@ -56,25 +56,10 @@ MediaVersion? _selectedVersion(List<MediaVersion>? versions, int versionIndex) {
 
 String? _formatResolution(MediaVersion version) {
   final raw = version.videoResolution?.trim();
-  if (raw != null && raw.isNotEmpty) return _formatResolutionValue(raw);
+  if (raw != null && raw.isNotEmpty) return resolutionDisplayLabel(raw);
 
   final fallback = resolutionLabelFromDimensions(version.width, version.height);
-  return fallback == null ? null : _formatResolutionValue(fallback);
-}
-
-String _formatResolutionValue(String value) {
-  final normalized = value.trim().toLowerCase();
-  if (normalized == '4k' || normalized == 'uhd') return '4K';
-  if (normalized == 'sd') return 'SD';
-
-  final numeric = RegExp(r'^(\d+)(?:p)?$').firstMatch(normalized);
-  if (numeric != null) {
-    final height = int.tryParse(numeric.group(1)!);
-    if (height != null && height >= 2160) return '4K';
-    return '${numeric.group(1)}p';
-  }
-
-  return value.toUpperCase();
+  return fallback == null ? null : resolutionDisplayLabel(fallback);
 }
 
 MediaStream? _firstStreamOfKind(MediaVersion version, MediaStreamKind kind) {

lib/utils/resolution_label.dart

@@ -3,8 +3,8 @@
 /// height for non-standard sizes). Returns `null` when [height] is null.
 ///
 /// Plex hands the label back already in its `Media.videoResolution` field;
-/// Jellyfin only gives raw pixel dimensions, so the Jellyfin mapper and
-/// playback path both call this to produce the same shape.
+/// Jellyfin only gives raw pixel dimensions, which the Jellyfin mapper feeds
+/// through [resolutionLabelFromDimensions] to produce the same shape.
 String? resolutionLabelFromHeight(int? height) {
   if (height == null) return null;
   if (height >= 2160) return '4k';
@@ -23,3 +23,24 @@ String? resolutionLabelFromDimensions(int? width, int? height) {
   if ((width != null && width >= 854) || (height != null && height >= 480)) return '480';
   return resolutionLabelFromHeight(height);
 }
+
+final _numericResolutionValue = RegExp(r'^(\d+)(?:p)?$');
+
+/// Format a canonical resolution label — or a raw numeric height, with or
+/// without a trailing `p` — for display: `'1080'`/`'1080p'` → `'1080p'`,
+/// `'4k'`/`'uhd'`/heights ≥ 2160 → `'4K'`, `'sd'` → `'SD'`; anything else is
+/// uppercased verbatim.
+String resolutionDisplayLabel(String value) {
+  final normalized = value.trim().toLowerCase();
+  if (normalized == '4k' || normalized == 'uhd') return '4K';
+  if (normalized == 'sd') return 'SD';
+
+  final numeric = _numericResolutionValue.firstMatch(normalized);
+  if (numeric != null) {
+    final height = int.tryParse(numeric.group(1)!);
+    if (height != null && height >= 2160) return '4K';
+    return '${numeric.group(1)}p';
+  }
+
+  return value.trim().toUpperCase();
+}

lib/widgets/rating_bottom_sheet.dart

@@ -542,11 +542,7 @@ class _RatingBottomSheetState extends State<RatingBottomSheet> {
     return () => nodes[index].requestFocus();
   }
 
-  String _backendLabel(MediaBackend backend) => switch (backend) {
-    MediaBackend.plex => 'Plex',
-    MediaBackend.jellyfin => 'Jellyfin',
-    MediaBackend.emby => 'Emby',
-  };
+  String _backendLabel(MediaBackend backend) => backend.dialect?.productName ?? 'Plex';
 }
 
 const _serverKey = 'server';