patches: restructure per reviewer feedback

Major changes:
1. Zoom separated into standalone patch 0000
   - UAZoomChangeFocus in ns_draw_window_cursor
   - Fallback in ns_update_end for window-switch tracking
   - No overlayZoomActive (source of split/switch/move bug)

2. VoiceOver patches 0001-0008 are now Zoom-free
   - All UAZoom*, overlayZoom*, kUAZoomFocus references removed
   - lastAccessibilityCursorRect kept for VoiceOver bounds queries
   - Commit messages cleaned of Zoom references

3. README.txt and TESTING.txt rewritten for new structure

Addresses reviewer (Stéphane Marks) feedback:
- Keep Zoom patch separate from VoiceOver work
- Design discussion needed for non-Zoom patches
- Performance: ns-accessibility-enabled=nil for zero overhead

patches/0001-ns-add-accessibility-base-classes-and-text-extractio.patch

@@ -1,4 +1,4 @@
-From 2730f8ddf26bfe5f5fb7553793fc537f45d46476 Mon Sep 17 00:00:00 2001
+From 84a96f2f60f2db10cc3d38bc68ccb7d2404b6ad5 Mon Sep 17 00:00:00 2001
 From: Martin Sukany <martin@sukany.cz>
 Date: Sat, 28 Feb 2026 12:58:11 +0100
 Subject: [PATCH 1/8] ns: add accessibility base classes and text extraction