On an iPhone, Markers, Channel names and Settings open as a panel, not over Stop (#250)

[Skeyelab]

Closes #250 (iPhone). The iPad and Mac panels are #255.

What changed

• Portrait: Markers, Channel names and Settings open as a panel where the meters are. The transport stays below it, so Stop and Marker can be reached mid-Take.
• Landscape: the panel sits beside the meters. They get narrower but keep their height. The transport column doesn't move.
• iPad and Mac: unchanged, still sheets, until UX: iPad and Mac docked panels (Markers, Shows) beside the meters #255.
• LivePanelPlacement (Kit, tested first) chooses over the meters, beside them, or a sheet, from the size classes.
• Channel label tap (from the whole-app review): on an iPhone it opens the Channel names panel. Before, it opened a modal alert with a keyboard over Stop and Marker. iPad and Mac keep the alert.
• Channel numbers stay on one line. With a panel open in landscape, "10" to "18" had wrapped to two lines, which made those meters about 13 pt shorter.
• Launch flags: -showSettings and -channelNames now open the same way a tap does. New -showMarkers, for screenshots.

How it was checked

• LivePanelPlacementTests: portrait, landscape (small and Max) and regular width. Written first; they failed before the type existed.
• Simulator, iPhone 17, during a running Take (-demoSignal -demoRecord):
  • Portrait: each of the three panels opens over the meters, with Stop and Marker visible below. With the Markers panel open, tapping Marker took the count from 0 to 1 and the Marker appeared in the list.
  • Landscape: Markers and Settings open beside the meters, with Stop and Marker in the right-hand column.
  • Meter height with a panel open: channels 1-9 end at y 356.7 pt and 10-18 at 357.7 pt. With no panel, all 18 end at 356.7.
• ./scripts/verify.sh passes: 434 package tests, macOS and iOS Simulator builds.
• Not run on a real iPhone. Screenshots were sent to Eric in the session.

Already there before, not changed here

• In landscape the warning banner ("No Drive…") covers the tops of the meters, with or without a panel.
• In landscape the Settings panel shows little at a time and has to be scrolled.

https://claude.ai/code/session_013qdugNZbXwKKz5gPzzi2CL