Fix compatibility with current STS2 combat API

[Zamiell]

Hello and thanks for the amazing API! I'm attempting to write a machine learning bot to get good at playing STS2, so I am building on top of your work. However, I found this bug. The below description is from a LLM:

Summary

• replace CombatManager.Instance.IsPlayPhase calls with a helper based on current combat state/manager properties
• update MerchantRoom.Inventory usages to GetLocalInventory()
• allow target resolution against ICombatState

Validation

• dotnet build "STS2_MCP.csproj" -c Release -o "out\STS2_MCP" -p:STS2GameDir="C:\Program Files (x86)\Steam\steamapps\common\Slay the Spire 2" --no-restore
• installed the rebuilt mod locally and verified GET /api/v1/singleplayer works during combat, returning state_type: "monster" and battle.is_play_phase: true

Context

With the current STS2 build, combat state reads fail with:

MissingMethodException: CombatManager.get_IsPlayPhase()

The current game API exposes related state through CombatState.CurrentSide plus CombatManager phase flags instead of IsPlayPhase.

[Gennadiyev]

Hi, thanks for your interest in the mod and thanks for the PR!

It seems that your fix can be a duplicate of PR #75. For players on the beta branch, this should be the right way to go. We will be integrating this patch after 0.104+ becomes stable.

I'm sorry, but I do not have the capacity to maintain the mod for the beta branch. While automated tests are now easy with agents, I still try to make changes incremental and systematically tested.

Please let me know if you I interpret the pull request wrong 🙇

[Zamiell]

ok, thanks for the quick reply!
i have a lot of other improvements to STS2MCP that I am using, like debug warping to specific combats, but I will just run on my fork for now until you are ready for pull requests.

[G07cha]

Seems like already covered by the merged #123