Fix build and code structure improvements. New but essential UI functionality. CI improvements. Documentation improvements. AI module improvements.

src/Signals/StellaOps.Signals/Program.cs

@@ -875,6 +875,7 @@ signalsGroup.MapPost("/reachability/recompute", async Task<IResult> (
 
 app.Run();
 
+// Make Program class public for WebApplicationFactory<Program> test support
 public partial class Program
 {
     internal static bool TryAuthorize(HttpContext httpContext, string requiredScope, bool fallbackAllowed, out IResult? failure)
@@ -935,3 +936,5 @@ public partial class Program
         return false;
     }
 }
+
+// Primary Program partial declaration merged above