A kind: model-provider plugin is loaded by providers/ discovery and never enters the
PluginManager hook lifecycle, so transform_api_error_classification was unreachable for it
without shipping a second plugin component. The profile now carries an optional
classify_api_error(error, *, status_code, error_code, message, body, model) callable,
consulted as a classifier stage right after the generic plugin hooks and only for the
provider that produced the error. None or an unknown reason leaves the built-in verdict;
built-in providers are untouched (no name table, no lifecycle change).
Also: a plugin refresh_credential returning None/empty was treated as a successful refresh
(row marked ok, stale bearer replayed up to the refresh cap). It now benches the row like a
failed refresh POST, so the loop rotates or falls to the generic sign-in copy.
Part of #116408
(cherry picked from commit b8129fd6fd6a0cf4eeee6d95a5d5d823668a306d)
bce20d0b1f