feat(ui): move workspace controls to a bar under the simulators

[lauridskern]

Summary

Moves the workspace's tools menu and platform menu out of the simulator header into their own bar.

• Sidebar panel: a full-width bar under the simulators holds the tools menu on the left and the platform menu on the right (justify-between). When both platforms are visible, it spans both simulators. Both menus open upward.
• Fullscreen, or no visible platform: the same bar stays above the tools, as before. That keeps the platform menu reachable when the simulator area is collapsed.
• One component: the bar is a single shared nav. The old ml-auto and per-placement menu alignment conditionals are gone, and SimulatorView no longer takes a toolbar prop. The device picker now starts at the left of the simulator header.
• Docs: docs/devices.md describes where the two menus are.

The final commit bumps the version to 0.1.141.

Telemetry

None. This only moves existing controls; surface and layout attribution are unchanged.

Testing

• The workspace UI test now checks every layout (iOS, Android, both, none) for exactly one bar with the tools menu first and the platform menu second. It also checks the bar sits directly under the simulators unless no platform is visible, and that neither menu remains in a simulator header.
• UI, panel and layout tests pass (43). tsc reports only the five existing SelectItem id errors in workspace.tsx.
• Built and installed locally as 0.1.141. The layout was not checked visually in a browser: the panel freezes outside the Codex host.
• The device settings gear still sits at the bottom right of each simulator, now just above the platform menu.