Follow every slot of a multi-slot run

Stations that test many units at once now get an operator view built for the fixture instead of a single-unit screen.

• Added a fixture grid with one tile per slot showing its name, serial, current phase and status, sized to fill the screen from 2 to 80 slots
• Added slot pages with each slot's own phases, prompts, outcome and run link, reachable from the grid or a direct link
• Improved the progress bar to show one group per slot with its phases, and a violet state wherever a slot waits on the operator
• Updated the CLI to report slot names, units and outcomes so every slot gets its own run in the dashboard