Add health condition list, tick, and save for phase 77.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.Simulation/School.cs

@@ -348,7 +348,7 @@ public sealed class School : IDisposable
         }
     }
 
-    /// <summary>Runs one fixed step of the school: calendar, yearly intake, applicant refresh, presence, actions, need decay, then apparel wear.</summary>
+    /// <summary>Runs one fixed step of the school: calendar, yearly intake, applicant refresh, presence, actions, need decay, apparel wear, then health conditions.</summary>
     /// <returns><see langword="true"/> when the roster, applicant pool or wardrobe changed this step.</returns>
     public bool Tick(double deltaTime, double gameMinutesPerRealSecond)
     {
@@ -442,6 +442,7 @@ public sealed class School : IDisposable
             peopleChanged |= AffinitySystem.Apply(this, talked);
         }
 
+        peopleChanged |= HealthConditionSystem.Apply(this, gameMinutes);
         peopleChanged |= RosterTalkDirty;
         RosterTalkDirty = false;
         return peopleChanged;