op-challenger: Disable moves for permissioned games

op-challenger monitors permissioned games so it can resolve them and reclaim bonds. It also checks if it should perform moves even though it typically isn't the CHALLENGER and so its moves would be rejected. We could reduce the number of L1 RPC calls made significantly if the challenger only checked what steps to perform if it's tx sender was the authorised CHALLENGER role for permissioned games.

Start by locating the op-challenger move-decision and permissioned-game handling entry points, then trace how the transaction sender and CHALLENGER authorization are determined. Confirm the existing move checks and L1 RPC behavior; done means unauthorized challengers skip move-step checks while authorized challengers retain current behavior, with relevant tests passing.

Written by the indexing model from the issue text.