Morse controller

Its a controller for a Morse-code light artwork: a unit that reads text files from a USB stick, transmits the text as Morse code by pulsing a chandelier of ~20 mains dimmable LED bulbs between an adjustable minimum glow and maximum brightness (two front-panel knobs), and displays the scrolling text on a 4:3 monitor. It must work unmodified on 100–240V/50–60Hz across UK, EU and US, boot unattended in under 60 seconds, survive daily hard power cuts, and be built entirely from off-the-shelf, long-availability parts so further units can be assembled from documentation alone in ten years' time. The engineer delivers a working prototype, schematics, BOM, firmware source, assembly instructions and an enclosure spec (client fabricates the casing); fixed price across three milestones, full IP assignment to Work Untitled Ltd.