Show the cluster's solar weather in a bandmap status bar

The reader follows N1MM's rules for WWV and WCY lines and the sh/wwv
table. The bar is hidden until the cluster has sent some.

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

tests/Nonemm.Spotting.Tests/SolarReaderTests.cs

@@ -0,0 +1,34 @@
+namespace Nonemm.Spotting.Tests;
+
+public class SolarReaderTests
+{
+    [Theory]
+    [InlineData("WWV de VE7CC <18Z> : SFI=140, A=5, K=2, No Storms -> No Storms\a\a")]
+    [InlineData("WCY de DK0WCY-1 <19> : K=2 expK=2 A=5 R=0 SFI=140 SA=qui GMF=qui Au=no")]
+    [InlineData("WWV: SFI=140 A=5 K=2")]
+    public void AnnouncementLinesAreKeptAsTheNodeSentThem(string line) =>
+        Assert.Equal(line.TrimEnd('\a'), new SolarReader().Read(line));
+
+    [Fact]
+    public void TheLineUnderAShWwvHeaderIsLabelled()
+    {
+        SolarReader reader = new();
+
+        Assert.Null(reader.Read("Date        Hour   SFI   A   K Forecast          Logger"));
+        Assert.Equal("SFI/A/K: 24-Oct-2026 1200Z 140 5 2 No Storms", reader.Read("24-Oct-2026 1200Z  140   5   2 No Storms"));
+    }
+
+    [Fact]
+    public void ASpotCancelsTheHeader()
+    {
+        SolarReader reader = new();
+        reader.Read("Date Hour SFI A K Forecast Logger");
+        reader.Read("DX de K1TTT: 14025.0 JA1XYZ CW 1205Z");
+
+        Assert.Null(reader.Read("some other line"));
+    }
+
+    [Fact]
+    public void OrdinaryLinesAreNotSolarWeather() =>
+        Assert.Null(new SolarReader().Read("DX de K1TTT: 14025.0 JA1XYZ CW 26 dB 1205Z"));
+}