Add admin database download

RpgRoller.Tests/HostingCoverageTests.cs

@@ -23,6 +23,23 @@ public sealed class HostingCoverageTests
         Assert.Contains(services, d => d.ServiceType == typeof(IDiceRoller));
     }
 
+    [Fact]
+    public void AddRpgRollerCore_WithFileConnectionString_RegistersResolvedSqliteDatabaseFile()
+    {
+        var services = new ServiceCollection();
+        var contentRoot = Path.Combine(Path.GetTempPath(), $"rpgroller-hosting-{Guid.NewGuid():N}");
+        var configuration = new ConfigurationBuilder().AddInMemoryCollection(new Dictionary<string, string?> { ["ConnectionStrings:RpgRoller"] = "Data Source=App_Data/rpgroller.db" }).Build();
+        var environment = new TestWebHostEnvironment { ContentRootPath = contentRoot };
+
+        services.AddRpgRollerCore(configuration, environment);
+
+        using var provider = services.BuildServiceProvider();
+        var databaseFile = provider.GetRequiredService<SqliteDatabaseFile>();
+
+        Assert.Equal(Path.Combine(contentRoot, "App_Data", "rpgroller.db"), databaseFile.Path);
+        Assert.True(Directory.Exists(Path.Combine(contentRoot, "App_Data")));
+    }
+
     [Fact]
     public void SqliteSchemaUpgrader_MigratesLegacySchema()
     {