feat/17-print-panel-ui
- Ensure unstructured Task closures in TargetWorkflowViewModel and Stage2View run on @MainActor after awaiting CupsService / spool. Without this, updates in the failure path were not reaching the UI in time, failing Milestone3UITests. - lpoptions parser: a token no longer truncates the whole parse. UI test results: Milestone3UITests 6/6 pass; Core tests 154/154 pass; universal arm64 x86_64 build passes.