Combine multiple lifespans into a single lifespan.Useful when mounting FastMCP into FastAPI and you need to run
both your app’s lifespan and the MCP server’s lifespan.Works with both FastAPI-style lifespans (yield None) and FastMCP-style
lifespans (yield dict). Results are merged; later lifespans override
earlier ones on key conflicts.Lifespans are entered in order and exited in reverse order (LIFO).Args:
*lifespans: Lifespan context manager factories to combine.