OpenAPI Overlays for Environment Promotion Across Dev, Staging, and Production

I keep finding these forgotten corners of my use cases for OpenAPI Overlays roundup that nobody talks about, and environment promotion is the one I get the most quietly frustrated about. Because the way most teams handle it today is with three copies of the same OpenAPI file. There’s a dev version, a staging version, and a production version, and they’re identical except for the server URLs, the token endpoints, and a rate-limit note or two.