Automatically monitors Anti-Gravity model quotas and switches the default model to the one with the highest remaining quota. If all Anti-Gravity models are below 20%, it falls back to the native `gemini-flash` model.

自动监控反重力模型的配额，并将默认模型切换至剩余配额最高的模型。若所有反重力模型配额均低于20%，则回退至原生的gemini-flash模型。