Add JSON config, DB-backed library options, and docs

- Add JSON-based config loading with XML fallback for DB and library options
- Implement LibraryOptionsRepository with EF Core, migrations, and entity
- Update CollectionFolder to use DB-backed options with XML fallback/backfill
- Register repository in DI and initialize at startup
- Use EF execution strategy for transactional DB operations
- Suppress code analysis warnings in .csproj and test files
- Add DATABASE_MIGRATION.md, LIBRARY_OPTIONS_DB_DESIGN.md, and WEBSOCKET_AUTHENTICATION.md
- Add database.json.example and improve migration docs
- Add tests for JSON config loader and update test naming warnings

Jellyfin.Server.Implementations/Item/ChapterRepository.cs

@@ -77,21 +77,25 @@ public class ChapterRepository : IChapterRepository
     public async Task SaveChaptersAsync(Guid itemId, IReadOnlyList<ChapterInfo> chapters, CancellationToken cancellationToken = default)
     {
         await using var context = _dbProvider.CreateDbContext();
-        await using var transaction = await context.Database.BeginTransactionAsync(cancellationToken).ConfigureAwait(false);
 
-        await context.Chapters
-            .Where(e => e.ItemId.Equals(itemId))
-            .ExecuteDeleteAsync(cancellationToken)
-            .ConfigureAwait(false);
-
-        for (var i = 0; i < chapters.Count; i++)
+        // Use the execution strategy to handle transactional consistency and retries
+        // This is required for PostgreSQL NpgsqlRetryingExecutionStrategy
+        var executionStrategy = context.Database.CreateExecutionStrategy();
+        await executionStrategy.ExecuteAsync(async () =>
         {
-            var chapter = chapters[i];
-            await context.Chapters.AddAsync(Map(chapter, i, itemId), cancellationToken).ConfigureAwait(false);
-        }
+            await context.Chapters
+                .Where(e => e.ItemId.Equals(itemId))
+                .ExecuteDeleteAsync(cancellationToken)
+                .ConfigureAwait(false);
 
-        await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
-        await transaction.CommitAsync(cancellationToken).ConfigureAwait(false);
+            for (var i = 0; i < chapters.Count; i++)
+            {
+                var chapter = chapters[i];
+                await context.Chapters.AddAsync(Map(chapter, i, itemId), cancellationToken).ConfigureAwait(false);
+            }
+
+            await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
+        }).ConfigureAwait(false);
     }
 
     /// <inheritdoc />