tests(calendar): Add calendar render tests (#3)

- updates calendar to support overriding the current day when rendering
- supports current culture when rendering
- renames Calendar to CalendarGenerator

tests/ModuleTests/Calendar/StartDayOfWeekTests.cs

@@ -0,0 +1,35 @@
+using System.Text;
+using ModuleCore.Calendar;
+
+namespace ModuleTests.Calendar;
+
+public class StartDayOfWeekTests
+{
+	private static readonly VerifySettings Settings;
+
+	static StartDayOfWeekTests()
+	{
+		Settings = new VerifySettings();
+		var testBaseDirectory = Path.Join(TestConstants.SnapshotFolderName, nameof(StartDayOfWeekTests));
+
+		Settings.UseDirectory(testBaseDirectory);
+		Settings.DisableDiff();
+	}
+
+	[Fact]
+	public Task StartOfDayRender()
+	{
+		Settings.UseFileName(nameof(StartOfDayRender));
+
+		var date = new DateTime(2026, 8, 1);
+		var sb = new StringBuilder();
+		foreach (var dayOfWeek in Enum.GetValues<DayOfWeek>())
+		{
+			var calendar = new CalendarGenerator(startOfWeek: dayOfWeek);
+			sb.AppendLine($"Start Day: {dayOfWeek}");
+			sb.AppendLine(calendar.Render(date, date));
+		}
+
+		return Verify(sb, Settings);
+	}
+}