Add an optional “suggested companion parts” prompt when adding parts to an estimate/work order, similar to how packages can trigger add-on recommendations. Example: when a drain plug is added (06L…), Protractor prompts “Add matching crush washer (06K…)?”, with a one-click add option. This should be configurable (on/off), support part-to-part relationships (one-to-one and one-to-many), and reduce missed hardware/seals that commonly accompany core parts.