[Feature] Allow switch from Max,etc to API and back w/o logout/login

It's a typical workflow during intense coding sessions, especially when running multiple claude code instances, to need to switch to API usage when you hit your Max (and presumably Pro) limits. Currently you have to logout and back in entirely to do this.

Also as i think about it, with that in place it'd be even more useful to have the ability to 'fall back' to API when you hit your Max/Pro limits. Presumably this would also have a couple options. Falling back when you hit the overall limit, or say when you want to stick to Opus and your Max config is about to fall back to Sonnet. Obviously with similar warnings to what we get today with the Opus->Sonnet model fallback , perhaps with a configurable confirmation as well.