Sign in once; every later session (in any functai language) uses it: lm15
keeps the sign-in in its credentials file, shared by every language.
Subscriptions ("claude", "chatgpt", "copilot") open a browser, or
print a link or code over SSH; for an API provider ("openai",
"anthropic", "groq", ...) the key is asked for, or given as key, and
saved. ai_logins() lists the providers this machine is signed in to (no
secrets shown); ai_logout() forgets one.