Surgery and running recovery?

Hi, I'm 33 M. I finished c25k multiple times over the years but I managed to train pretty consistently from July 2023 until late January 2026. I'm getting shoulder surgery next month so once I recover I'm hoping to run more consistently again. I did the Philly half in November 2025 in 2:26:00 which is a PR for me.

I really don't want to have to start from scratch again. Does anyone have advice on maintaining running fitness before and after operations? My doctor told me don't run in the meantime and to fix my arm first. TIA