refactor: type server identifiers

lib/services/plex_api_cache.dart

@@ -1,4 +1,5 @@
 import 'dart:convert';
+import '../media/ids.dart';
 
 import 'package:drift/drift.dart';
 
@@ -39,7 +40,7 @@ class PlexApiCache extends ApiCache {
 
   /// Delete cached data for a specific item (when removing a download).
   @override
-  Future<void> deleteForItem(String serverId, String ratingKey) async {
+  Future<void> deleteForItem(ServerId serverId, String ratingKey) async {
     final metadataKey = '$serverId:/library/metadata/$ratingKey';
     final childrenKey = '$serverId:/library/metadata/$ratingKey/children';
 
@@ -49,11 +50,11 @@ class PlexApiCache extends ApiCache {
   }
 
   @override
-  Future<void> pinForOffline(String serverId, String ratingKey) async {
+  Future<void> pinForOffline(ServerId serverId, String ratingKey) async {
     return pin(serverId, '/library/metadata/$ratingKey');
   }
 
-  Future<void> unpinForOffline(String serverId, String ratingKey) async {
+  Future<void> unpinForOffline(ServerId serverId, String ratingKey) async {
     return unpin(serverId, '/library/metadata/$ratingKey');
   }
 
@@ -61,14 +62,14 @@ class PlexApiCache extends ApiCache {
   ///
   /// Named `isPinnedRatingKey` to avoid colliding with the inherited
   /// [ApiCache.isPinned]'s identical Dart signature.
-  Future<bool> isPinnedRatingKey(String serverId, String ratingKey) {
+  Future<bool> isPinnedRatingKey(ServerId serverId, String ratingKey) {
     return isPinned(serverId, '/library/metadata/$ratingKey');
   }
 
   // Rating keys can be alphanumeric, not just numeric.
   static final RegExp _metadataKeyPattern = RegExp(r'/library/metadata/([^/]+)$');
 
-  Future<Set<String>> getPinnedKeys(String serverId) => extractPinnedIds(serverId, _metadataKeyPattern);
+  Future<Set<String>> getPinnedKeys(ServerId serverId) => extractPinnedIds(serverId, _metadataKeyPattern);
 
   /// Fetch and parse a [MediaItem] from cache.
   ///
@@ -77,7 +78,7 @@ class PlexApiCache extends ApiCache {
   /// [MediaItem] at the boundary. Returns `null` when the endpoint is not
   /// cached or contains no metadata.
   @override
-  Future<MediaItem?> getMetadata(String serverId, String ratingKey) async {
+  Future<MediaItem?> getMetadata(ServerId serverId, String ratingKey) async {
     final cached = await get(serverId, '/library/metadata/$ratingKey');
     final container = PlexCacheParser.extractMediaContainer(cached);
     final json = PlexCacheParser.extractFirstMetadata(cached);
@@ -108,7 +109,7 @@ class PlexApiCache extends ApiCache {
   /// callers passing them have a more accurate read of server state.
   @override
   Future<void> applyWatchState({
-    required String serverId,
+    required ServerId serverId,
     required String itemId,
     required bool isWatched,
     int? viewOffsetMs,
@@ -116,7 +117,7 @@ class PlexApiCache extends ApiCache {
     int? viewedLeafCount,
   }) async {
     final endpoint = '/library/metadata/$itemId';
-    final cached = await get(serverId, endpoint);
+    final cached = await get(ServerId(serverId), endpoint);
     final json = PlexCacheParser.extractFirstMetadata(cached);
     if (cached == null || json == null) return;
     if (isWatched) {
@@ -130,12 +131,12 @@ class PlexApiCache extends ApiCache {
       if (lastViewedAt != null) json['lastViewedAt'] = lastViewedAt;
     }
     if (viewedLeafCount != null) json['viewedLeafCount'] = viewedLeafCount;
-    await put(serverId, endpoint, cached);
+    await put(ServerId(serverId), endpoint, cached);
   }
 
   /// Load all pinned Plex metadata in a single query.
   ///
-  /// Returns a map keyed by `buildGlobalKey(serverId, ratingKey)` for O(1)
+  /// Returns a map keyed by `buildGlobalKey(ServerId(serverId), ratingKey)` for O(1)
   /// lookups. Used by DownloadProvider to batch-load metadata on startup
   /// instead of issuing per-item DB queries.
   @override
@@ -151,7 +152,7 @@ class PlexApiCache extends ApiCache {
           final container = PlexCacheParser.extractMediaContainer(data);
           final json = PlexCacheParser.extractFirstMetadata(data);
           if (json == null) continue;
-          result[buildGlobalKey(entry.serverId, entry.id)] = PlexMappers.mediaItemFromCacheJson(
+          result[buildGlobalKey(ServerId(entry.serverId), entry.id)] = PlexMappers.mediaItemFromCacheJson(
             _withContainerLibrary(json, container),
             serverId: entry.serverId,
           );