Take a QTC header that is only a series number as ten lines

An operator copying a header off the air often types the series number and
nothing else. That read as a header the program could not parse, so the box
went yellow and Close refused to log the series.

N1MM fills the count in: "If he only types the batch number without the
forward slash and count, the program will assume the count is 10."

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0157i7PiZyqBkquxS9A6FTdQ

src/Nonemm.Session/QtcTraffic.cs

@@ -214,16 +214,23 @@ public sealed class QtcTraffic
 
     /// The header a station sends in front of a series: a series number, a
     /// separator and how many lines follow. Anything between the two numbers
-    /// counts as the separator, because it is copied off the air.
+    /// counts as the separator, because it is copied off the air. A series
+    /// number on its own means ten lines, which is what N1MM assumes: "If he
+    /// only types the batch number without the forward slash and count, the
+    /// program will assume the count is 10."
     public static (int Series, int Count)? ReadHeader(string text)
     {
         string[] parts = text.Trim().ToUpperInvariant().Replace("QTC", "").Trim()
             .Split(['/', '-', ' ', '\\'], StringSplitOptions.RemoveEmptyEntries);
-        return parts.Length >= 2
-            && int.TryParse(parts[0], out int series)
-            && int.TryParse(parts[1], out int count)
-            && series > 0
-            && count is > 0 and <= WaeQtc.MostPerSeries
+        if (parts.Length == 0 || !int.TryParse(parts[0], out int series) || series <= 0)
+        {
+            return null;
+        }
+        if (parts.Length == 1)
+        {
+            return (series, WaeQtc.MostPerSeries);
+        }
+        return int.TryParse(parts[1], out int count) && count is > 0 and <= WaeQtc.MostPerSeries
             ? (series, count)
             : null;
     }