plugin used by sidecare when all application in single repo

[PengLingJun]

Sidecar plugins can only be applied to a repo in an auto-discovered way. But I hope that the actual plugin is based on the application. When the sidecar is doing automatic discovery, it cannot read any environment variables of the application. In this way, sidecare is limited. If you want to use plugins, you can only use one repo and one application.