test(battle-node): wire-shape test + refresh stale comment for v1.1

Final-review follow-ups:
- BuildOpponentTurnStart's doc comment claimed the v1 client sits
  indefinitely — true before the loop closure, false after. Updated
  to describe the pair with BuildOpponentTurnEnd.
- TypedBodyWireShapeTests had no coverage for BuildOpponentTurnEnd;
  added the literal-JSON test so a future JsonPropertyName rename
  on TurnEndBody is caught.

SVSim.BattleNode/Lifecycle/ScriptedLifecycle.cs

@@ -99,9 +99,10 @@ public static class ScriptedLifecycle
                 Spin: ScriptedProfiles.ReadySpin));
 
     /// <summary>
-    /// Generic TurnStart push used to transition the client into "Opponent's turn…" state
-    /// after the player's TurnEnd. v1 doesn't simulate the opponent — once this lands the
-    /// client sits at the opponent-turn display indefinitely.
+    /// First half of the v1.1 scripted opponent turn cycle: pushed after the player's
+    /// TurnEnd, transitions the client into "Opponent's turn…" state. Paired with
+    /// <see cref="BuildOpponentTurnEnd"/>, which immediately follows and hands control
+    /// back to the player.
     /// </summary>
     public static MsgEnvelope BuildOpponentTurnStart() =>
         EnvelopeForPush(NetworkBattleUri.TurnStart,