-type file_id() :: binary().
-type id() :: binary().
-type provider() :: anthropic | openai.
-spec create(provider(), binary() | string()) -> {ok, id()} | {error, term()}.
-spec delete(provider(), id()) -> ok | {error, term()}.
-spec files_add(provider(), id(), [binary() | string()]) -> {ok, map()} | {error, term()}.
-spec files_remove(provider(), id(), [file_id()]) -> ok | {error, term()}.