fix(app): use the iPhone Duo top band beside the status region (#8901)

On the iPhone Duo inner screen in portrait, the workspace header, the left
sidebar's first row and the explorer tab rail now use the top band beside
the status region. The status region is published as the window's top-right
obstruction, the same slot desktop window controls use, so the row owning
that corner pads past it. Content gains 56pt.

Refs #7924

Co-authored-by: Elsa Granger <zeyugao@outlook.com>

packages/app/modules/paseo-window-layout/ios/PaseoWindowLayoutModule.swift

@@ -18,6 +18,8 @@ final class WindowLayoutView: ExpoView {
   private var barGuide: UILayoutGuide?
   private var barEdge = "none"
   private var bottomBarGuide: UILayoutGuide?
+  private var topBarGuide: UILayoutGuide?
+  private var occlusions: [CGRect] = []
   private var measuredBounds = CGRect.zero
 
   required init(appContext: AppContext? = nil) {
@@ -38,6 +40,7 @@ final class WindowLayoutView: ExpoView {
     super.didMoveToWindow()
     previousPayload = nil
     bottomBarGuide = nil
+    topBarGuide = nil
     setNeedsUpdateConstraints()
     scheduleUpdate()
   }
@@ -62,6 +65,8 @@ final class WindowLayoutView: ExpoView {
     if #available(iOS 27.1, *) {
       // UIKit tracks these reads and invalidates constraints when regions change.
       divisions = reservedRegions(kind: .division).compactMap { $0.isActive ? $0.frame : nil }
+      // Frames already include the system's interactive margins.
+      occlusions = reservedRegions(kind: .occlusion).compactMap { $0.isActive ? $0.frame : nil }
       let edge: String
       switch traitCollection.verticalBarEdge {
       case .leading: edge = "leading"
@@ -73,6 +78,11 @@ final class WindowLayoutView: ExpoView {
         // screen's corners rather than the rectangular safe area.
         bottomBarGuide = layoutGuide(for: .bar(onEdge: UIRectEdge.bottom, extent: 44))
       }
+      if topBarGuide == nil {
+        // Where a top bar rests. Beside a partial status region it can start above the
+        // rectangular safe area; content still keeps out of the occlusions.
+        topBarGuide = layoutGuide(for: .bar(onEdge: UIRectEdge.top, extent: 44))
+      }
       if edge != barEdge {
         barEdge = edge
         barGuide = edge == "none" ? nil : layoutGuide(
@@ -106,11 +116,17 @@ final class WindowLayoutView: ExpoView {
     if let bottomBar = bottomBarGuide?.layoutFrame, bottomBar.height > 0 {
       bottomClearance = max(0, bounds.maxY - bottomBar.maxY)
     }
+    var topBar: Any = NSNull()
+    if let frame = topBarGuide?.layoutFrame, frame.width > 0, frame.height > 0 {
+      topBar = rect(frame)
+    }
     let payload: [String: Any] = [
       "bounds": rect(bounds),
       "verticalBarEdge": barEdge,
       "verticalBar": barPayload,
       "bottomClearance": bottomClearance,
+      "topBar": topBar,
+      "occlusions": occlusions.map(rect),
       "divisions": divisions.map(rect)
     ]
     guard !NSDictionary(dictionary: payload).isEqual(to: previousPayload ?? [:]) else { return }