Grid maze solver with keys, doors and bombs, AI-assisted

You get a small existing codebase that models a grid maze and an AI assistant you may use. Fix a bug in the provided code, then find the shortest path from start to exit, then add keys that open matching doors (the search state now includes which keys you hold), and finally allow a limited number of bombs that clear walls. You are graded on how you steer and check the assistant as much as on the final code.