Mark the CQ frequency on the bandmap and leave Run when the radio moves off it

Starting Run stores the frequency in the position. The bandmap draws a
purple, bold "CQ Frequency" pseudospot there, which is not added to the
shared bandmap, and a click on it tunes back and sets Run. A move of more
than 3 kHz (a setting on the telnet Filters tab) while running switches
to search and pounce.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

tests/Nonemm.Session.Tests/OperatingPositionTests.cs

@@ -25,6 +25,45 @@ public class OperatingPositionTests
         CountryPrefix = "DL",
     };
 
+    [Fact]
+    public void RunningRemembersTheFrequencyItStartedOn()
+    {
+        OperatingPosition position = Session();
+        position.Tune(Frequency.FromKilohertz(14_025));
+
+        position.IsRunning = true;
+        position.Tune(Frequency.FromKilohertz(14_026));
+
+        Assert.Equal(Frequency.FromKilohertz(14_025), position.CqFrequency);
+        Assert.True(position.IsRunning);
+    }
+
+    [Fact]
+    public void MovingFarOffTheCqFrequencyGoesBackToSearching()
+    {
+        OperatingPosition position = Session();
+        position.Tune(Frequency.FromKilohertz(14_025));
+        position.IsRunning = true;
+
+        position.Tune(Frequency.FromKilohertz(14_028.5));
+
+        Assert.False(position.IsRunning);
+        Assert.Equal(Frequency.FromKilohertz(14_025), position.CqFrequency);
+    }
+
+    [Fact]
+    public void TheDistanceThatEndsRunningIsSet()
+    {
+        OperatingPosition position = Session();
+        position.CqLeaveHertz = 1_000;
+        position.Tune(Frequency.FromKilohertz(14_025));
+        position.IsRunning = true;
+
+        position.Tune(Frequency.FromKilohertz(14_026.5));
+
+        Assert.False(position.IsRunning);
+    }
+
     /// N1MM's `{FORCELOG}`: a contact the checks refuse still goes in the log,
     /// because one that was never logged cannot be fixed afterwards.
     [Fact]