Two custom overlays render outside every navigator column, so the
column-local safe area never reaches them. The thread arrangement Modal
read the presenting app's top and bottom insets and ignored the sides,
so its rows could run under the folded Duo's corner camera and status
column. The command palette sized itself from the window with a fixed
margin and centered itself across a book fold.

- The arrangement Modal measures its own safe area with a nested
  SafeAreaProvider, on all four edges.
- The palette stays inside the window's side insets and moves to the
  roomier side of a book fold, using the reserved-region bounds the
  thread composer already uses.
- The device preview's reveal handle moves off a book fold. That screen
  is already inset by NativeColumnContent, as is the MCP app's full
  screen header, so neither adds side insets of its own.
- Settings' filter and Close drop horizontal-only. UIKit hides those
  items when no horizontal bar is present, and the outer display lays
  sheet controls out vertically.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>