Add rolemaster automatic retry rolls

RpgRoller/Services/RolemasterRetryPolicy.cs

@@ -0,0 +1,32 @@
+namespace RpgRoller.Services;
+
+public static class RolemasterRetryPolicy
+{
+    public static int? ResolveAutoRetryBonus(int firstResult)
+    {
+        if (firstResult is >= 77 and <= 90)
+            return 5;
+
+        if (firstResult is >= 91 and <= 110)
+            return 10;
+
+        return null;
+    }
+
+    public static int? TryExtractRetryBonus(string? breakdown)
+    {
+        if (string.IsNullOrWhiteSpace(breakdown))
+            return null;
+
+        if (breakdown.Contains(RetryPlusFiveMarker, StringComparison.Ordinal))
+            return 5;
+
+        if (breakdown.Contains(RetryPlusTenMarker, StringComparison.Ordinal))
+            return 10;
+
+        return null;
+    }
+
+    public const string RetryPlusFiveMarker = "; retry(+5):";
+    public const string RetryPlusTenMarker = "; retry(+10):";
+}