feat(battle-node): relay uList on PvP PlayActions

Forwards the sender's deck-sourced summons/fetches to the opponent
(closes the spin-independent slice of direct-to-field summons). uList
coexists with the synthesized knownList in the same frame.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleNode/Sessions/Dispatch/Handlers/PlayActionsHandler.cs

@@ -42,11 +42,18 @@ internal sealed class PlayActionsHandler : IFrameHandler
         var played = KnownListBuilder.BuildPlayedCard(deckMap, playIdx, orderList);
         var oppoTargets = KnownListBuilder.RenameTargets(entries.GetValueOrDefault("targetList"));
 
+        // Deck-sourced movements (fetch / search / summon-from-deck) ride the uList — a verbatim,
+        // separate receive slot the node forwards unchanged (bullet-3 audit F1). The node makes no
+        // reveal decision; cardId presence is the sender's call. Coexists with the synthesized
+        // knownList in the same frame (capture line 75).
+        var uList = KnownListBuilder.RelayUList(entries.GetValueOrDefault("uList"));
+
         var body = new PlayActionsBroadcastBody(
             PlayIdx: playIdx,
             Type: type,
             KnownList: played is null ? null : new[] { played },
             OppoTargetList: oppoTargets,
+            UList: uList,
             // {type,cardId} forwarded so the opponent renders the choice token; selectCard dropped
             // when open==0 (hidden draw-to-hand pick). Null for a vanilla play (no keyAction).
             KeyAction: KnownListBuilder.StripKeyActionForOpponent(keyAction));