Copilot instructions

1---
2applyTo:
3  - "**/Platform/iOS/MauiView.cs"
4  - "**/Platform/iOS/MauiScrollView.cs"
5  - "**/Platform/iOS/*SafeArea*"
6---
7 
8# Safe Area Guidelines (iOS/macCatalyst)
9 
10## Platform Differences
11 
12| | macOS 14/15 | macOS 26+ |
13|-|-------------|-----------|
14| Title bar inset | ~28px | ~0px |
15| Used in CI | ✅ | ❌ |
16 
17Local macOS 26+ testing does NOT validate CI behavior. Fixes must pass CI on macOS 14/15.
18 
19| Platform | `UseSafeArea` default |
20|----------|-----------------------|
21| iOS | `false` |
22| macCatalyst | `true` |
23 
24## Architecture (PR #34024)
25 
26**`IsParentHandlingSafeArea`** — before applying adjustments, `MauiView`/`MauiScrollView` walk ancestors to check if any ancestor handles the **same edges**. If so, descendant skips (avoids double-padding). Edge-aware: parent handling `Top` does not block child handling `Bottom`. Result cached in `bool? _parentHandlesSafeArea`; cleared on `SafeAreaInsetsDidChange`, `InvalidateSafeArea`, `MovedToWindow`. `AppliesSafeAreaAdjustments` is `internal` for cross-type ancestor checks.
27 
28**`EqualsAtPixelLevel`** — safe area compared at device-pixel resolution to absorb sub-pixel animation noise (`0.0000001pt` during `TranslateToAsync`), preventing oscillation loops (#32586, #33934).
29 
30## Anti-Patterns
31 
32**❌ Window Guard** — comparing `Window.SafeAreaInsets` to filter callbacks blocks legitimate updates. On macCatalyst + custom TitleBar, `WindowViewController` pushes content down, changing the **view's** `SafeAreaInsets` without changing the **window's**. Caused 28px CI shift (macOS 14/15 only). Never gate per-view callbacks on window-level insets.
33 
34**❌ Semantic mismatch** — `_safeArea` is filtered by `GetSafeAreaForEdge` (zeroes edges per `SafeAreaRegions`); raw `UIView.SafeAreaInsets` includes all edges. Never compare them — compare raw-to-raw or adjusted-to-adjusted.
35