feat(cli): import cloud transcript on create_session (#13483)

* feat(cli): import cloud transcript on create_session

* fix(cli): satisfy typecheck for in-process cloud import

Provide the helper's effect services from the group context so the
HTTP import handler keeps the base request graph. Map the tagged
helper errors via Effect.match instead of matchEffect.

* refactor(server): remove dead cloud-import error fields

* fix(cli): restore clone workspace files only after attach