Calculation Editor: black areas while the Code Change question is open #308

From the 9.0.0 release test (Linux, 2026-10-12). Changing the code of a calculation (ECCE-QM → NWChem) opens the question "This calculation was set up for ECCE-QM. Change it to NWChem?". While it is open, the code icons, the Runtype field, the status line and the message area of the editor are drawn as black boxes; they come back after answering. The icon part was addressed in 9780dc6 (disabled bitmaps greyed with alpha), but the cause is broader: most likely the editor is held frozen (Freeze/UpdateHold) while the modal question is shown, so the areas it uncovers are not repainted. Release the hold before showing the question, or repaint on its close.