Show the other computers, and apply the ten-minute rule

Three pieces on top of the link:

**The network status window**, on the entry window's Window menu. A row
per station, this computer included the way N1MM shows it: number,
address, operator, band, mode, run, transmit, pass frequency, the last
message type, how long ago it arrived, the counts each way and the echo
round trip. A station that broadcast the wrong version is named under the
table in red — that is the one fault where everything looks connected
and nothing arrives. The box at the bottom sends a line of chat, and
Echo asks every station whether it is there.

**Where this station is** goes out once a second when it has changed.
The frequency, the mode and run have a dozen places they can change from
— the radio moving, a band button, a QSY typed into the callsign box —
so it is read and compared rather than announced from each of them.

**The ten-minute rule.** `BandChangeRules` already counted changes and
the stay on a band, and the entry window already showed the countdown,
but only a user-defined contest carried a rule, so every built-in
contest allowed anything. `ForCategory` gives a multi-operator entry
with one or two transmitters a ten-minute stay, which is N1MM's fallback
in `ContestInstance.BandChangeTimerDuration` for every contest that does
not name its own. Its per-contest table is a few hundred cases in a
decompiled hash switch and is not repeated.

Config ▸ Edit Networked-Computer Names now covers both networks: the
12060 broadcast to other programs and the 12070 link, with the station
number, the port, the version to claim and stations named by address for
a network where a broadcast does not reach.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PdAYHcdRktqKry7nk414TU

tests/Nonemm.Contests.Tests/BandChangeRulesTests.cs

@@ -14,6 +14,58 @@ public class BandChangeRulesTests
             TimestampUtc = Start.AddMinutes(minutes).AddSeconds(seconds),
         };
 
+    /// N1MM's fallback, which is the ten-minute rule: a multi-operator entry
+    /// with one transmitter has to stay ten minutes on a band, and nothing caps
+    /// how many times it may move.
+    [Theory]
+    [InlineData("MULTI-ONE", "ONE", 10)]
+    [InlineData("MULTI-OP", "ONE", 10)]
+    [InlineData("MULTI-TWO", "TWO", 10)]
+    [InlineData("MULTI-OP", "TWO", 10)]
+    [InlineData("MULTI-OP", "UNLIMITED", 0)]
+    [InlineData("SINGLE-OP", "ONE", 0)]
+    public void TheCategoryAloneSaysHowLongAStationStaysOnABand(
+        string operatorCategory,
+        string transmitters,
+        int minutes)
+    {
+        BandChangeRules rules = BandChangeRules.ForCategory(new ContestEntry
+        {
+            OperatorCategory = operatorCategory,
+            TransmitterCategory = transmitters,
+        });
+
+        Assert.Equal(TimeSpan.FromMinutes(minutes), rules.MinimumStay);
+        Assert.False(rules.IsCounted);
+    }
+
+    /// A contest that says nothing about band changes still gets the rule for
+    /// the category, which is what N1MM does.
+    [Fact]
+    public void AContestThatSaysNothingStillGetsTheTenMinuteRule()
+    {
+        Contest contest = new Rules.CqWorldWide(ModeCategory.Cw);
+
+        BandChangeRules rules = contest.BandChangesFor(new ContestEntry
+        {
+            OperatorCategory = "MULTI-ONE",
+            TransmitterCategory = "ONE",
+        });
+
+        Assert.True(rules.HasStayTimer);
+        Assert.Equal(TimeSpan.FromMinutes(10), rules.MinimumStay);
+    }
+
+    [Fact]
+    public void ASingleOperatorEntryHasNoBandChangeRule()
+    {
+        Contest contest = new Rules.CqWorldWide(ModeCategory.Cw);
+
+        Assert.Equal(
+            BandChangeRules.None,
+            contest.BandChangesFor(new ContestEntry { OperatorCategory = "SINGLE-OP" }));
+    }
+
     [Fact]
     public void EachMoveToAnotherBandIsOneChange() =>
         Assert.Equal(