This commit backs out part of a previous solver behavior change that always ran pretty-action computation during heap entailment, which could trigger unwanted side effects even when pretty printing was not requested. It introduces a new global pretty_print flag, wires it to a --pprint CLI option, and makes the solver choose compute_pretty_actions only when that flag is enabled, otherwise falling back to the normal action path. The result is safer default execution with pretty-printing preserved as an explicit opt-in.