Hygiene B6b: convert leaky-world tests + HudSystem cosmetics

- 10 EditMode files: every bare trailing world.Dispose() now inside using(world){} (single-world) or a [TearDown]+List<World> (the multi-world reject-matrix tests in BoonApplyTests/RouteSelectSystemTests) — an assertion failure can no longer leak the World and mask the true first failure. No test logic changed.
- HudSystem: collapse the blank-line run before the class close; trim the extracted route-map clause from the READY-panel comment.

466/466 EditMode tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Assets/_Project/Tests/EditMode/BoonOfferTests.cs

@@ -55,6 +55,8 @@ namespace ProjectM.Tests
         public void OfferSystem_DealsOncePerRoom_ExpeditionOnly_PerPlayerSeeds()
         {
             var world = new World("BoonOfferTest");
+            using (world)
+            {
             var group = world.GetOrCreateSystemManaged<SimulationSystemGroup>();
             group.AddSystemToUpdateList(world.GetOrCreateSystem<BoonOfferSystem>());
             group.SortSystems();
@@ -98,7 +100,7 @@ namespace ProjectM.Tests
             group.Update();
             Assert.AreEqual(0, em.GetComponentData<BoonOffer>(out1).Pending, "one deal per RoomEpoch (latch)");
 
-            world.Dispose();
+            }
         }
     }
 }