Yavsc.Api.Client is the new home for high-level HTTP clients
(BlogApiClient, CircleApiClient, BlogAclApiClient, etc.). It
depends on the host application's transport layer, but the host
(PostIt) is a UI app with OIDC, settings, and an ApplicationData
directory — none of which the abstract client library should
know about.
The IYavscApiClient interface captures just the transport
surface those clients need:
- HttpClient (so the client can configure BaseAddress)
- CallAsync<T> and CallAsync (the JSON over HTTP verb)
It deliberately leaves out LoginAsync / TrySilentLoginAsync /
CurrentAccessToken / HasValidSession / Settings — those are
authentication and configuration concerns, not transport. They
stay on the concrete YavscApiClient in PostIt.Services.
The concrete YavscApiClient now implements IYavscApiClient; the
existing public surface is unchanged (no breaking changes for
existing call sites in PostIt or the tests).
This commit only lays the foundation. The actual high-level
clients (Blog/Circle/BlogAcl) land in a follow-up commit that
re-uses this interface, so this one stays a small, reviewable
refactor.
