fix(challenge,scene): challenge id auto-detect, real ScRsp ids, teleport ownership

Round-2 fixes from the 01:44-01:53 client session:

- StartChallenge (MoC/PF/AS normal start) decoded challenge_id=0 -> client
  retried and aborted. detectChallengeID scans top-level varints for the
  first plausible id (challenge_data + known mode ranges) when the strict
  tag-14 decode misses; payload hexdump logged when still 0
- StartChallengeScRsp now carries stage_info (tag 13) with boss node buff
  echo, per the 4.6.51 proto
- GetSwitchHandData replies 8108 (the real ScRsp) - 8104 is
  SwitchHandStartCsReq, we were sending a request id back at the client
- GetSceneMapInfo: strict proto parse failed on some payloads (layout
  drift) which stalled the map UI ('no pillars / navigation loading') -
  now a raw handler with a lenient wire walk fallback + hexdump logging
- teleport destination ('AA teleport landed in AP'): teleport ids repeat
  on every floor and teleports.json was scanned globally in random map
  order. Map clicks now resolve floor-first via scene_identifier, and the
  global id scan never touches teleports.json
- tierce: arena 3014101 -> 3000101 fallback (client has no MapEntrance
  3014101), same as StartChallenge

internal/gameserver/dispatch.go

@@ -79,7 +79,7 @@ func handleNamed[ReqT any, RspT any](name, rspName string, fn func(s *Session, r
 		if len(payload) > 0 {
 			if m, okc := any(req).(proto.Message); okc {
 				if err := proto.Unmarshal(payload, m); err != nil {
-					PacketLog(fmt.Sprintf("[ERROR] Failed to decode cmd_id %d (%s): %v", reqID, name, err))
+					PacketLog(fmt.Sprintf("[ERROR] Failed to decode cmd_id %d (%s): %v payload=%s", reqID, name, err, hexDump(payload, 256)))
 					return nil
 				}
 			}
@@ -127,6 +127,14 @@ func isDangerCmd(cmdID uint16) bool {
 	return false
 }
 
+// hexDump returns a bounded hex preview for debugging wire-format issues.
+func hexDump(b []byte, max int) string {
+	if len(b) > max {
+		b = b[:max]
+	}
+	return fmt.Sprintf("%x", b)
+}
+
 // DispatchMessage is the Go port of CommandHandler::on_message.
 func DispatchMessage(s *Session, cmdID uint16, payload []byte) {
 	PacketLog(fmt.Sprintf("[PACKET RECV] cmd_id: %d %s (len: %d)", cmdID, goproto.NameByCmdID[cmdID], len(payload)))

internal/gameserver/handlers_challenge_flow.go

@@ -567,10 +567,64 @@ func dedupeTruncate4(in []uint32) []uint32 {
 	return out
 }
 
+// looksLikeChallengeID: known challenge-id ranges across endgame modes.
+func looksLikeChallengeID(v uint64) bool {
+	switch {
+	case v >= 101 && v <= 119, v == 900,
+		v >= 1001 && v <= 1035,
+		v >= 2001 && v <= 2025,
+		v >= 3001 && v <= 3020,
+		v >= 5000 && v <= 5700,   // MoC floors incl. 4.6 phases
+		v >= 20000 && v <= 20300, // Pure Fiction
+		v >= 30000 && v <= 30300: // Apocalyptic Shadow
+		return true
+	}
+	cd := getChallengeData()
+	_, okC := cd.Challenges[uint32(v)]
+	_, okT := cd.Tierce[uint32(v)]
+	return okC || okT
+}
+
+// detectChallengeID: when the strict decoder misses the challenge id (field
+// layout drift between client builds), scan top-level varint fields for the
+// first value that looks like a challenge id.
+func detectChallengeID(payload []byte) (uint32, int) {
+	buf := payload
+	for len(buf) > 0 {
+		tag, n := readUvarint(buf)
+		if n == 0 {
+			break
+		}
+		buf = buf[n:]
+		wireType := uint32(tag & 0x7)
+		if wireType == 0 {
+			v, n2 := readUvarint(buf)
+			if n2 == 0 {
+				break
+			}
+			buf = buf[n2:]
+			if looksLikeChallengeID(v) {
+				return uint32(v), int(tag >> 3)
+			}
+		} else {
+			skipWireField(wireType, &buf)
+		}
+	}
+	return 0, 0
+}
+
 // handleStartChallenge ports handle_start_challenge: respond cmd 1787 with
-// retcode(3) + cur_challenge(5) + lineup_list(6) + scene(10).
+// retcode(3) + cur_challenge(5) + lineup_list(6) + scene(10) + stage_info(13).
 func handleStartChallenge(s *Session, payload []byte) error {
 	req := decodeStartChallengeReq(payload)
+	if req.challengeID == 0 {
+		if id, field := detectChallengeID(payload); id != 0 {
+			Log("handle_start_challenge: strict decode missed, detected challenge_id=" + itoa(int(id)) + " at field " + itoa(field))
+			req.challengeID = id
+		} else {
+			PacketLog("[CHALLENGE] challenge_id=0 payload=" + hexDump(payload, 128))
+		}
+	}
 	Log("handle_start_challenge: challenge_id=" + itoa(int(req.challengeID)))
 
 	chosenAvatars := req.firstAvatars
@@ -592,12 +646,13 @@ func handleStartChallenge(s *Session, payload []byte) error {
 		}
 	}
 
-	// fallback to the standard arena when the mapped one is missing from res
-	if res, err := common.GameRes(); err == nil {
-		if !mapHasEntry(res, entrance) {
-			Log("[CHALLENGE] Arena entrance missing in res.json, fallback to 3000101")
-			entrance = 3000101
-		}
+	// the 4.6.51 client has no MapEntrance 3014101 (Rust lesson: Lua
+	// GotoMapParam nil -> stuck loading) even though res.json has it
+	if entrance == 3014101 {
+		entrance = 3000101
+	} else if res, err := common.GameRes(); err == nil && !mapHasEntry(res, entrance) {
+		Log("[CHALLENGE] Arena entrance missing in res.json, fallback to 3000101")
+		entrance = 3000101
 	}
 
 	Log("[CHALLENGE] Start: challenge_id=" + itoa(int(req.challengeID)) + " (mapped " + itoa(int(baseID)) + ")")
@@ -640,6 +695,20 @@ func handleStartChallenge(s *Session, payload []byte) error {
 		return err
 	}
 
+	// 4.6.51: StartChallengeScRsp.stage_info (tag 13) - boss node info echoes
+	// the selected buff so the client can set up the challenge UI
+	stageInfo := &goproto.ChallengeStageInfo{}
+	if req.buffID != 0 {
+		stageInfo.BossInfo = &goproto.ChallengeBossInfo{
+			FirstNode:  &goproto.ChallengeBossSingleNodeInfo{BuffId: req.buffID},
+			SecondNode: &goproto.ChallengeBossSingleNodeInfo{BuffId: req.buffID},
+		}
+	}
+	stageBuf, err := proto.Marshal(stageInfo)
+	if err != nil {
+		return err
+	}
+
 	var body []byte
 	body = append(body, 0x18, 0x00) // tag 3: retcode = 0
 	body = append(body, 0x2A)       // tag 5: cur_challenge
@@ -651,6 +720,9 @@ func handleStartChallenge(s *Session, payload []byte) error {
 	body = append(body, 0x52) // tag 10: scene
 	body = appendUvarint(body, uint64(len(sceneBuf)))
 	body = append(body, sceneBuf...)
+	body = append(body, 0x6A) // tag 13: stage_info
+	body = appendUvarint(body, uint64(len(stageBuf)))
+	body = append(body, stageBuf...)
 
 	return s.SendRaw(&NetPacket{CmdType: 1787, Body: body})
 }
@@ -731,6 +803,15 @@ func handleStartChallengeTierce(s *Session, payload []byte) error {
 		}
 	}
 
+	// the 4.6.51 client cannot load arena 3014101 (no MapEntrance) - fall
+	// back to the standard arena, mirroring handleStartChallenge
+	if entrance == 3014101 {
+		entrance = 3000101
+	} else if res, err := common.GameRes(); err == nil && !mapHasEntry(res, entrance) {
+		Log("[CHALLENGE] Tierce arena entrance missing in res.json, fallback to 3000101")
+		entrance = 3000101
+	}
+
 	if player := s.JSON(); player != nil {
 		setChallengeBattleConfig(player, chosenAvatars, req.challengeID, event, buff)
 	}

internal/gameserver/handlers_scene.go

@@ -126,11 +126,24 @@ func init() {
 			// req.EntryId doubles as a floor id in some map flows
 			resolvedEntry = findEntryForFloor(res, req.EntryId)
 		case req.TeleportId != 0:
-			resolvedEntry = findEntryByTeleport(res, req.TeleportId, currentEntry())
+			floorID := uint32(0)
+			if sceneIdent != nil {
+				floorID = sceneIdent.FloorId
+			}
+			if entry := findEntryByTeleportInFloor(res, req.TeleportId, floorID); entry != 0 {
+				resolvedEntry = entry
+			} else {
+				resolvedEntry = findEntryByTeleport(res, req.TeleportId, currentEntry())
+			}
 		case sceneIdent != nil && sceneIdent.TeleportNigger != nil:
 			if t, okc := sceneIdent.TeleportNigger.(*goproto.SceneIdentifier_MDAIDPPKOPO); okc && t.MDAIDPPKOPO != nil && t.MDAIDPPKOPO.PLIDNBMCIJH != 0 {
-				// map teleport click: teleport id arrives via scene_identifier
-				resolvedEntry = findEntryByTeleport(res, t.MDAIDPPKOPO.PLIDNBMCIJH, currentEntry())
+				// map teleport click: teleport id + floor arrive via scene_identifier
+				tpID := t.MDAIDPPKOPO.PLIDNBMCIJH
+				if entry := findEntryByTeleportInFloor(res, tpID, sceneIdent.FloorId); entry != 0 {
+					resolvedEntry = entry
+				} else {
+					resolvedEntry = findEntryByTeleport(res, tpID, currentEntry())
+				}
 			}
 		case interactID != 0:
 			resolvedEntry = findEntryByInteract(res, interactID, currentEntry())
@@ -221,13 +234,33 @@ func init() {
 		return nil
 	})
 
-	handle("GetSceneMapInfo", func(s *Session, req *goproto.GetSceneMapInfoCsReq, rsp *goproto.GetSceneMapInfoScRsp) error {
+	// decodeSceneIdentifiersLenient: the 4.6.51 client's cmd-1461 payload can
+	// fail strict proto parsing (field layout drift between builds) — walk the
+	// wire format manually and pull floor_id/content_id out of field 2.
+	// GetSceneMapInfo as a raw handler: the 4.6.51 client's cmd-1461 payload
+	// can fail strict proto parsing (layout drift), so fall back to a manual
+	// wire walk instead of dropping the request (the map UI stalls without
+	// this reply - no pillars, "navigation loading").
+	rawHandlers[1461] = func(s *Session, payload []byte) error {
 		res, err := common.GameRes()
 		if err != nil {
 			return err
 		}
+		rsp := &goproto.GetSceneMapInfoScRsp{}
 
-		for _, si := range req.SceneIdentifiers {
+		var identifiers []*goproto.SceneIdentifier
+		var strictReq goproto.GetSceneMapInfoCsReq
+		if err := proto.Unmarshal(payload, &strictReq); err == nil {
+			identifiers = strictReq.SceneIdentifiers
+		}
+		if len(identifiers) == 0 {
+			identifiers = decodeSceneIdentifiersLenient(payload)
+			if len(identifiers) > 0 {
+				PacketLog("[SCENE] GetSceneMapInfo: used lenient decode (strict parse failed)")
+			}
+		}
+
+		for _, si := range identifiers {
 			floorID := si.FloorId
 			mapInfo := &goproto.SceneMapInfo{
 				FloorId:         floorID,
@@ -283,8 +316,9 @@ func init() {
 
 			rsp.SceneMapInfo = append(rsp.SceneMapInfo, mapInfo)
 		}
-		return nil
-	})
+
+		return s.Send(rsp)
+	}
 
 	handle("SceneEntityMove", func(s *Session, req *goproto.SceneEntityMoveCsReq, rsp *goproto.SceneEntityMoveScRsp) error {
 		player := s.JSON()
@@ -413,16 +447,35 @@ func mapHasEntry(res *common.JsonConfig, entryID uint32) bool {
 	return ok
 }
 
-func findEntryByTeleport(res *common.JsonConfig, teleportID uint32, fallback uint32) uint32 {
-	// teleports.json covers floors whose res config has no inline teleports:
-	// teleport id -> floor -> entry (via the floor name search)
-	for floorID, m := range common.Teleports() {
-		if _, ok := m[teleportID]; ok {
-			if entry := findEntryForFloor(res, floorID); entry != 0 {
-				return entry
+// findEntryByTeleportInFloor resolves a teleport inside a KNOWN floor
+// (map-teleport clicks always carry the floor in scene_identifier).
+func findEntryByTeleportInFloor(res *common.JsonConfig, teleportID, floorID uint32) uint32 {
+	if floorID != 0 {
+		suffix := fmt.Sprintf("_F%d", floorID)
+		entryIDs := sortedU32Keys2(res.LevelOutputConfigs)
+		for _, eid := range entryIDs {
+			for name, cfg := range res.LevelOutputConfigs[eid] {
+				if len(name) <= len(suffix) || name[len(name)-len(suffix):] != suffix {
+					continue
+				}
+				for _, sc := range cfg.Scenes {
+					if _, ok := sc.Teleports[teleportID]; ok {
+						return eid
+					}
+				}
 			}
 		}
+		// floor known but teleport not in its res config (teleports.json-only
+		// floors): the entry owning the floor is still the right destination
+		return findEntryForFloor(res, floorID)
 	}
+	return 0
+}
+
+func findEntryByTeleport(res *common.JsonConfig, teleportID uint32, fallback uint32) uint32 {
+	// NOTE: never scan teleports.json globally by id alone - teleport ids
+	// (1001, 1002, ...) repeat on every floor, which sent players to a random
+	// region ("AA teleport landed in AP").
 	entryIDs := sortedU32Keys2(res.LevelOutputConfigs)
 	for _, eid := range entryIDs {
 		names := make([]string, 0, len(res.LevelOutputConfigs[eid]))
@@ -466,6 +519,64 @@ func findEntryByInteract(res *common.JsonConfig, interactID uint32, fallback uin
 	return fallback
 }
 
+// decodeSceneIdentifiersLenient walks the raw wire format of a
+// GetSceneMapInfoCsReq payload: field 2 = repeated SceneIdentifier;
+// inside each: floor_id = 13 (varint), content_id = 7 (varint).
+func decodeSceneIdentifiersLenient(payload []byte) []*goproto.SceneIdentifier {
+	var out []*goproto.SceneIdentifier
+	buf := payload
+	for len(buf) > 0 {
+		tag, n := readUvarint(buf)
+		if n == 0 {
+			break
+		}
+		buf = buf[n:]
+		fieldNumber := uint32(tag >> 3)
+		wireType := uint32(tag & 0x7)
+
+		if fieldNumber == 2 && wireType == 2 {
+			l, n2 := readUvarint(buf)
+			if n2 == 0 || int(l) > len(buf[n2:]) {
+				break
+			}
+			sub := buf[n2 : n2+int(l)]
+			buf = buf[n2+int(l):]
+
+			si := &goproto.SceneIdentifier{}
+			for len(sub) > 0 {
+				stag, n3 := readUvarint(sub)
+				if n3 == 0 {
+					break
+				}
+				sfn := uint32(stag >> 3)
+				swt := uint32(stag & 0x7)
+				sub2 := sub[n3:]
+				if swt == 0 && sfn == 13 {
+					v, n4 := readUvarint(sub2)
+					if n4 == 0 {
+						break
+					}
+					sub = sub2[n4:]
+					si.FloorId = uint32(v)
+				} else if swt == 0 && sfn == 7 {
+					v, n4 := readUvarint(sub2)
+					if n4 == 0 {
+						break
+					}
+					sub = sub2[n4:]
+					si.ContentId = uint32(v)
+				} else {
+					skipWireField(swt, &sub)
+				}
+			}
+			out = append(out, si)
+		} else {
+			skipWireField(wireType, &buf)
+		}
+	}
+	return out
+}
+
 func sortedU32Keys2[V any](m map[uint32]V) []uint32 {
 	keys := make([]uint32, 0, len(m))
 	for k := range m {

persistent

@@ -6,15 +6,15 @@
     "3": 1004
   },
   "position": {
-    "x": 780,
-    "y": -153008,
-    "z": -621450,
-    "rot_y": 0
+    "x": 5379,
+    "y": 0,
+    "z": -2300,
+    "rot_y": 54387
   },
   "scene": {
-    "plane_id": 30141,
-    "floor_id": 30141001,
-    "entry_id": 3014101
+    "plane_id": 10000,
+    "floor_id": 10000000,
+    "entry_id": 100000304
   },
   "main_character": "FemaleHarmony",
   "march_type": "MarchHunt",