Pied Web UX 1.8.18

The reader reminder clock now uses the same borderless icon pipeline, optical size, stroke and action geometry as the surrounding Reply, Mark unread, Archive and Delete controls. Reminder and mailbox behavior are unchanged.\n\nVerified with the fictional reader fixture, 30 browser checks, 5 Python tests, a 58/58 production install check and an 80/80 read-only production audit.