Phase 40: clock tempo at 1 min/s, x5/x10 heavy stride.

src/HSchool.Simulation/ClockSpeed.cs

@@ -6,8 +6,8 @@ namespace HSchool.Simulation;
 /// </summary>
 public static class ClockSpeed
 {
-    /// <summary>×½, ×1, ×2, ×3, ×4.</summary>
-    public static ReadOnlySpan<double> Multipliers => [0.5d, 1d, 2d, 3d, 4d];
+    /// <summary>×½, ×1, ×2, ×5, ×10.</summary>
+    public static ReadOnlySpan<double> Multipliers => [0.5d, 1d, 2d, 5d, 10d];
 
     /// <summary>Index of ×1, the speed a school starts at.</summary>
     public const int DefaultIndex = 1;
@@ -18,4 +18,22 @@ public static class ClockSpeed
 
     /// <summary>Multiplier for a validated index; out-of-range values fall back to ×1.</summary>
     public static double MultiplierAt(int index) => IsValid(index) ? Multipliers[index] : Multipliers[DefaultIndex];
+
+    /// <summary>
+    /// Calendar impulses between heavy-system ticks. ×5 and ×10 stride so walking and needs keep
+    /// one game minute per heavy step instead of twenty tiny ones per second.
+    /// </summary>
+    public static int HeavySystemsStride(int speedIndex) => speedIndex switch
+    {
+        3 => 4,
+        4 => 2,
+        _ => 1,
+    };
+
+    /// <summary>
+    /// Game minutes passed into presence, needs and learning on a heavy tick. High speeds use a
+    /// fixed one-minute quantum; lower speeds pass the impulse's own advance.
+    /// </summary>
+    public static double HeavyGameMinutes(int speedIndex, double impulseMinutes) =>
+        speedIndex is 3 or 4 ? 1d : impulseMinutes;
 }