Tapping the presence line opens a list of who is here, the driver highlighted and guests with a colour dot; Escape or an outside tap closes it #398

Replaces #364 unchanged in scope; it now waits only on the who frame issue of this plan, not on the split #291. The presence line itself is on main (70c9eec).

Done:

• [ ] The presence line in the status strip is a button (at least 44 px) that sends {type:'who'} and shows the answer as a list. Text goes through textContent, the colour only through a validated #rrggbb style, and the driver is highlighted.
• [ ] The list closes on Escape or an outside tap and never moves the camera box.
• [ ] A test of the pure render helper: the driver is highlighted, a guest gets a dot, and a bad colour gets none.
• [ ] forge.json untouched, and bun --cwd Software/so101 test passes, including the first-visit gzip budget.