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/BaseItemRepository.cs

@@ -1088,8 +1088,10 @@ public sealed class BaseItemRepository
         var context = await _dbProvider.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
         await using (context.ConfigureAwait(false))
         {
-            var transaction = await context.Database.BeginTransactionAsync(cancellationToken).ConfigureAwait(false);
-            await using (transaction.ConfigureAwait(false))
+            // 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 ids = tuples.Select(f => f.Item.Id).ToArray();
                 var existingItems = await context.BaseItems
@@ -1284,8 +1286,7 @@ public sealed class BaseItemRepository
                 }
 
                 await context.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
-                await transaction.CommitAsync(cancellationToken).ConfigureAwait(false);
-            }
+            }).ConfigureAwait(false);
         }
     }
 
@@ -1299,8 +1300,10 @@ public sealed class BaseItemRepository
 
         await using (dbContext.ConfigureAwait(false))
         {
-            var transaction = await dbContext.Database.BeginTransactionAsync(cancellationToken).ConfigureAwait(false);
-            await using (transaction.ConfigureAwait(false))
+            // Use the execution strategy to handle transactional consistency and retries
+            // This is required for PostgreSQL NpgsqlRetryingExecutionStrategy
+            var executionStrategy = dbContext.Database.CreateExecutionStrategy();
+            await executionStrategy.ExecuteAsync(async () =>
             {
                 var userKeys = item.GetUserDataKeys().ToArray();
                 var retentionDate = (DateTime?)null;
@@ -1320,9 +1323,7 @@ public sealed class BaseItemRepository
                     .Where(e => e.ItemId == item.Id)
                     .ToArrayAsync(cancellationToken)
                     .ConfigureAwait(false);
-
-                await transaction.CommitAsync(cancellationToken).ConfigureAwait(false);
-            }
+            }).ConfigureAwait(false);
         }
     }