fix(gameserver): answer UI-gating cmds the 4.6.51 client stalls on

First real-client session (2026-10-07 01:00) showed the client walking and
attacking but UI interactions stalling: ~120 CsReq dropped with no reply.

- auto-empty responder: any unknown CsReq with a Cmd-enum ScRsp pair now
  gets an empty ScRsp, except the danger families (GridFight/ChessRogue/
  EvolveBuild/ChimeraDuel/Jukebox/CycleScore) which must stay dropped
  (client Sync(nil) NREs on empty, per the Rust lessons)
- GetUnreleasedBlockInfo: the Endgame entry waits on this - 4.6.51 wire is
  CsReq 4190 -> ScRsp 4112 retcode tag 14 (the Rust build answered 4130,
  an id this client never sends)
- SetClientPaused acked (client pauses itself when opening menus/map)
- explicit handlers: TakeQuestReward, GetFirstTalkNpc, QuitBattle,
  GetMapRotationData (Amphoreus teleport pillars), GetPamSkinData,
  GetAllServerPrefsData/UpdateServerPrefsData, GetHeartDialInfo, GetPetData,
  GetShopList
- SendRaw now logs (dummy/raw replies were invisible in gameserver.log)
- cmdpairs.go: req->rsp id pairs generated from the Cmd enum (865 pairs),
  stable across message renames
- smoke test extended: 4190->4112 and SetClientPaused ack verified

internal/gameserver/dummycheck_test.go

@@ -0,0 +1,26 @@
+package gameserver
+
+import (
+	"testing"
+
+	goproto "gac-hkrpg-go/protocol/proto"
+)
+
+func TestDispatchMapsRegistered(t *testing.T) {
+	t.Logf("typedHandlers=%d dummyResponses=%d rawHandlers=%d", len(typedHandlers), len(dummyResponses), len(rawHandlers))
+	if len(dummyResponses) == 0 {
+		t.Fatal("dummyResponses is EMPTY - handlers_raw.go init did not run")
+	}
+	if len(rawHandlers) == 0 {
+		t.Fatal("rawHandlers is EMPTY")
+	}
+	if _, ok := dummyResponses[17]; !ok {
+		t.Fatal("GetVideoVersionKeyCsReq (17) not in dummyResponses")
+	}
+	if _, ok := dummyResponses[uint16(goproto.CmdIDByName["GetSecretKeyInfoCsReq"])]; !ok {
+		t.Fatal("GetSecretKeyInfoCsReq not in dummyResponses")
+	}
+	if _, ok := rawHandlers[8115]; !ok {
+		t.Fatal("8115 GetSwitchHandData not in rawHandlers")
+	}
+}