Enhance school simulation and management by integrating roster functionality, allowing for the installation and persistence of student and staff data. Update the school architecture to include a roster alongside existing components, ensuring proper validation against map layouts. Revise room definitions to support homeroom designations and update related tests to validate new functionalities and ensure robustness in roster handling.

src/HSchool.Simulation/GameClock.cs

@@ -54,14 +54,16 @@ public sealed class GameClock
     /// Advances the calendar by one fixed step of <paramref name="realSeconds"/>, scaled by the
     /// base rate and the current speed. Does nothing while paused.
     /// </summary>
-    public void Advance(double realSeconds, double gameMinutesPerRealSecond)
+    /// <returns>Game minutes actually added; zero while paused.</returns>
+    public double Advance(double realSeconds, double gameMinutesPerRealSecond)
     {
         if (!IsRunning)
         {
-            return;
+            return 0;
         }
 
         var gameMinutes = realSeconds * gameMinutesPerRealSecond * Multiplier;
         Time = Time.AddMinutes(gameMinutes);
+        return gameMinutes;
     }
 }