patches: fix childFrameLastBuffer ivar init order

The Qnil initialization was in patch 0000 (Zoom) but the ivar
declaration is in patch 0008 (child frame tracking).  Moved the
init to patch 0008 so each patch compiles independently.

patches/0006-doc-add-VoiceOver-accessibility-section-to-macOS-app.patch

@@ -1,4 +1,4 @@
-From 6e03e0051d7f15bd1391ff5c5b9d2093711d4300 Mon Sep 17 00:00:00 2001
+From 472c446d629dc95c5c71560af5de3462943ff84a Mon Sep 17 00:00:00 2001
 From: Martin Sukany <martin@sukany.cz>
 Date: Sat, 28 Feb 2026 12:58:11 +0100
 Subject: [PATCH 7/9] doc: add VoiceOver accessibility section to macOS