SignatureTests: only a gun is tapped; a beam burns while its trigger is held

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

tests/Aetheria.Shared.Tests/SignatureTests.cs

@@ -172,7 +172,7 @@ public sealed class SignatureTests : IDisposable
         }
         r.Ship.SetTarget(TargetRef.None);
         r.Weapon.Activate();
-        r.Weapon.Deactivate();
+        if (r.Weapon is InstantWeapon) r.Weapon.Deactivate(); // a gun is tapped; a beam burns while held
         for (var i = 0; i < 5; i++) r.Zone.Update(.1f);
     }