Refactor SQLite Database Provider

- Removed unused classes and files related to SQLite database provider, including SqliteDesignTimeJellyfinDbFactory, ModelBuilderExtensions, PragmaConnectionInterceptor, AssemblyInfo, SqliteDatabaseProvider, DateTimeKindValueConverter.
- Updated tests to remove dependencies on removed classes and adjusted mocking for configuration sections.
- Added Microsoft.EntityFrameworkCore.Sqlite package reference to test project.
- Improved string handling in tests for better consistency and clarity.
- Refactored logging methods in JellyfinApplicationFactory for better readability and maintainability.

src/Jellyfin.Database/Jellyfin.Database.Providers.Postgres/SnakeCaseHistoryRepository.cs

@@ -0,0 +1,33 @@
+// <copyright file="SnakeCaseHistoryRepository.cs" company="PlaceholderCompany">
+// Copyright (c) PlaceholderCompany. All rights reserved.
+// </copyright>
+
+#pragma warning disable EF1001 // NpgsqlHistoryRepository is an internal EF Core infrastructure type; intentional use in this PostgreSQL fork.
+
+namespace Jellyfin.Database.Providers.Postgres;
+
+using Microsoft.EntityFrameworkCore.Migrations;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Migrations.Internal;
+
+/// <summary>
+/// A custom history repository that uses snake_case column names for the
+/// <c>__EFMigrationsHistory</c> table, matching the PostgreSQL naming convention
+/// used throughout this fork.
+/// </summary>
+public sealed class SnakeCaseHistoryRepository : NpgsqlHistoryRepository
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="SnakeCaseHistoryRepository"/> class.
+    /// </summary>
+    /// <param name="dependencies">Repository dependencies injected by EF Core.</param>
+    public SnakeCaseHistoryRepository(HistoryRepositoryDependencies dependencies)
+        : base(dependencies)
+    {
+    }
+
+    /// <inheritdoc/>
+    protected override string MigrationIdColumnName => "migration_id";
+
+    /// <inheritdoc/>
+    protected override string ProductVersionColumnName => "product_version";
+}