fix(scene): persist scene only after the client actually moves

The user's save was bricked by teleporting to entry 100000304: the client
offers it in the map but NREs in AdventurePhase._EnterStep1_InitializeMapInfo
while loading, and the server had already saved that scene - every login
then replayed the broken scene (stuck on the train-window loading screen).

- loadScene no longer calls SavePersistent; SceneEntityMove's 5s cadence
  persists the scene only once the client walks in it (the existing arena
  guard already kept challenge scenes out of the save)
- reset persistent to entry 102020107 (proven walkable in the 01:00/01:38
  sessions)

internal/gameserver/handlers_scene.go

@@ -842,11 +842,14 @@ func loadScene(s *Session, entryID uint32, isEnterScene bool, teleportID *uint32
 	sceneInfo.EntityGroupList = append(sceneInfo.EntityGroupList, playerGroup)
 
 	if isEnterScene {
+		// in-memory only: the scene is persisted by SceneEntityMove once the
+		// client actually moves. Saving here would brick the save when the
+		// client cannot load the destination (e.g. entry 100000304) - every
+		// login would then NRE in AdventurePhase on the same broken scene.
 		player.Scene.EntryID = entryID
 		player.Scene.FloorID = floorID
 		player.Scene.PlaneID = planeID
 		player.Position = jsonPos
-		player.SavePersistent()
 
 		if err := s.Send(&goproto.EnterSceneByServerScNotify{
 			Scene:  sceneInfo,