prep docs and service updates

src/Excititor/StellaOps.Excititor.WebService/Options/GraphOptions.cs

@@ -0,0 +1,11 @@
+namespace StellaOps.Excititor.WebService.Options;
+
+/// <summary>
+/// Configuration for graph linkouts and overlays.
+/// </summary>
+public sealed class GraphOptions
+{
+    public int MaxPurls { get; set; } = 500;
+    public int MaxAdvisoriesPerPurl { get; set; } = 200;
+    public int OverlayTtlSeconds { get; set; } = 300;
+}