docs: remove draggable overlay description and fix Android z-order docs

Agent-Logs-Url: https://github.com/DIPSAS/DIPS.Mobile.UI/sessions/eb3d2f31-1908-4999-89ec-bb2e2b05989b

Co-authored-by: Vetle444 <35739538+Vetle444@users.noreply.github.com>

Author: Copilot

src/library/DIPS.Mobile.UI/API/Diagnostics/LayoutDiagnosticsOverlay.cs

@@ -11,7 +11,7 @@ namespace DIPS.Mobile.UI.API.Diagnostics;
 
 /// <summary>
 /// A floating overlay pill for layout diagnostics.
-/// Collapsed: small draggable pill indicator. Expanded: panel with live status.
+/// Collapsed: small pill indicator. Tap to expand and see live status, start/stop controls, and snapshot info.
 /// </summary>
 internal class LayoutDiagnosticsOverlay : Grid
 {

wiki/Layout-Diagnostics.md

@@ -80,8 +80,8 @@ Common causes of high measure counts:
 
 The diagnostics overlay is a floating pill that stays visible over all content, including modals and bottom sheets:
 
-- **iOS**: Rendered in a separate `UIWindow` at `UIWindowLevel.Alert - 1`
-- **Android**: Uses `TranslationZ` for z-ordering and re-parents to dialog `DecorView` when dialogs open
+- **iOS**: Rendered in a separate `UIWindow` at `UIWindowLevel.Alert - 1` with touch passthrough via `HitTest` override
+- **Android**: Re-parented to the dialog `DecorView` when dialogs open, managed via `FragmentLifeCycleCallback`
 
 Tap the pill to expand and see live recording status, start/stop controls, and the current snapshot summary.