BallisticFlightTests: using System for the Subscribe lambda; DrawAhead comment names no frame clock

Builds headless; Unity still on the old Projectile at this commit.

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

Assets/Scripts/ServerShared/DrawAhead.cs

@@ -40,7 +40,7 @@ public static class DrawAhead
     }
 
     // A ballistic round at a sim time (the clock's Zone.Time + Lead): on FireControl's line for what the sim has published
-    // of its outcome, with the barrel's offset from that line decaying to nothing over blendTime sim seconds from FireTime.
+    // of its outcome, with the barrel's offset from that line decaying to nothing over blendTime sim seconds from the moment of firing.
     public static float3 Round(in PendingShot shot, ShotResult? known, float3 barrel, float blendTime, float time) =>
         Lifted(shot, FireControl.RoundAt(shot, known, time), barrel, blendTime, time);
 

tests/Aetheria.Shared.Tests/BallisticFlightTests.cs

@@ -2,6 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+using System;
 using System.Linq;
 using Xunit;
 using static CultMath.math;