Rederive login/logout provider options from runtime.getProviders() +
listCredentials() + getProviderAuthStatus() instead of the removed
authStorage.getOAuthProviders()/list()/get() + getAll()/
getProviderDisplayName() surface (Pi 0.80.8+).
- Replace the AuthProviderModelRegistry structural interface with a
runtime-shaped AuthProviderRuntime (getProviders/listCredentials/
getProviderAuthStatus); a real ModelRuntime satisfies it.
- Make getLoginProviderOptions/getLogoutProviderOptions async to match
the await call sites already in authService.ts.
- OAuth-capable providers = auth.oauth present; api-key providers =
auth.apiKey present, preserving OAUTH_ONLY_PROVIDERS /
isApiKeyLoginProvider logic. Display names from Provider.name.
- Update the test double to the new runtime shape.
Slice 2 of the authStorage migration relay. tsc: 31 -> 28 errors
(remaining are cross-slice: slices 3/4/5).