Refactor PostgreSQL provider: multi-schema & async prep

- Refactor migrations and provider to use multiple PostgreSQL schemas, each matching a legacy SQLite database (activitylog, authentication, displaypreferences, library, users).
- All tables, foreign keys, and indexes are now schema-qualified; Down migration drops tables by schema.
- Provider ensures schemas exist before migrations; entities are mapped to correct schemas in OnModelCreating.
- Add support for max-pool-size, min-pool-size, and multiplexing connection options; update logging accordingly.
- VACUUM ANALYZE now runs per schema during scheduled optimization.
- TruncateAllTablesAsync now truncates tables with schema qualification.
- README updated with schema structure, new options, and multiplexing warnings.
- CacheDecorator now calls async repository methods using .GetAwaiter().GetResult(), with documentation.
- Lays groundwork for full async/await and multiplexing support in the database layer.

MediaBrowser.Providers/MediaInfo/AudioFileProber.cs

@@ -154,7 +154,9 @@ namespace MediaBrowser.Providers.MediaInfo
 
             audio.HasLyrics = mediaStreams.Any(s => s.Type == MediaStreamType.Lyric);
 
-            _mediaStreamRepository.SaveMediaStreams(audio.Id, mediaStreams, cancellationToken);
+            await _mediaStreamRepository
+                .SaveMediaStreamsAsync(audio.Id, mediaStreams, cancellationToken)
+                .ConfigureAwait(false);
         }
 
         /// <summary>

MediaBrowser.Providers/MediaInfo/EmbeddedImageProvider.cs

@@ -138,7 +138,11 @@ namespace MediaBrowser.Providers.MediaInfo
             }
 
             // Try attachments first
-            var attachmentStream = _mediaSourceManager.GetMediaAttachments(item.Id)
+            var attachments = await _mediaSourceManager
+                .GetMediaAttachmentsAsync(item.Id, cancellationToken)
+                .ConfigureAwait(false);
+
+            var attachmentStream = attachments
                 .FirstOrDefault(attachment => !string.IsNullOrEmpty(attachment.FileName)
                     && imageFileNames.Any(name => attachment.FileName.Contains(name, StringComparison.OrdinalIgnoreCase)));
 

MediaBrowser.Providers/MediaInfo/FFProbeVideoInfo.cs

@@ -278,9 +278,13 @@ namespace MediaBrowser.Providers.MediaInfo
 
             video.HasSubtitles = mediaStreams.Any(i => i.Type == MediaStreamType.Subtitle);
 
-            _mediaStreamRepository.SaveMediaStreams(video.Id, mediaStreams, cancellationToken);
+            await _mediaStreamRepository
+                .SaveMediaStreamsAsync(video.Id, mediaStreams, cancellationToken)
+                .ConfigureAwait(false);
 
-            _mediaAttachmentRepository.SaveMediaAttachments(video.Id, mediaAttachments, cancellationToken);
+            await _mediaAttachmentRepository
+                .SaveMediaAttachmentsAsync(video.Id, mediaAttachments, cancellationToken)
+                .ConfigureAwait(false);
 
             if (options.MetadataRefreshMode == MetadataRefreshMode.FullRefresh
                 || options.MetadataRefreshMode == MetadataRefreshMode.Default)