patches: review fixes — defvar, method extraction, GC safety, window_end_valid

Review-based improvements:
- ns-accessibility-enabled DEFVAR_BOOL (disable AX overhead)
- window_end_valid guard in ns_ax_window_end_charpos
- GC safety comments on Lisp_Object ObjC ivars
- postAccessibilityNotificationsForFrame split into 4 methods
- block_input in ns_ax_completion_text_for_span
- Fplist_get predicate comment
- macos.texi VoiceOver section with defvar docs
- README updated with USER OPTION + REVIEW CHANGES sections

patches/README.txt

@@ -3,10 +3,10 @@ EMACS NS VOICEOVER ACCESSIBILITY PATCH
 patch: 0001-ns-implement-AXBoundsForRange-for-macOS-Zoom-cursor-.patch
         0002-doc-add-VoiceOver-accessibility-section-to-macOS-app.patch
 author: Martin Sukany <martin@sukany.cz>
-files: src/nsterm.h (+105 lines)
-        src/nsterm.m (+2846 ins, -151 del, +2695 net)
-        doc/emacs/macos.texi (+46 lines)
-        etc/NEWS (+11 lines)
+files: src/nsterm.h (+119 lines)
+        src/nsterm.m (+3024 ins, -147 del, +2877 net)
+        doc/emacs/macos.texi (+53 lines)
+        etc/NEWS (+13 lines)
 
 
 OVERVIEW
@@ -114,6 +114,18 @@ ARCHITECTURE
       accessibilityAttributeValue:forParameter: API.
 
 
+USER OPTION
+-----------
+
+  ns-accessibility-enabled (DEFVAR_BOOL, default t):
+    When nil, the accessibility virtual element tree is not built, no
+    notifications are posted, and ns_draw_phys_cursor skips the Zoom
+    update.  This eliminates accessibility overhead entirely on systems
+    where assistive technology is not in use.  Guarded at three entry
+    points: postAccessibilityUpdates, ns_draw_phys_cursor, and
+    windowDidBecomeKey.
+
+
 THREADING MODEL
 ---------------
 
@@ -615,4 +627,38 @@ TESTING CHECKLIST
     26. Open an org-mode file with many folded sections.  Verify that
         folded (invisible) text is not announced during navigation.
 
+
+REVIEW CHANGES (post initial implementation)
+---------------------------------------------
+
+  The following changes were made based on maintainer-style code review:
+
+  1. ns_ax_window_end_charpos: added window_end_valid guard.  Falls
+     back to BUF_ZV when the window has not been fully redisplayed,
+     preventing stale data in AX getters called before next redisplay.
+
+  2. GC safety documentation: detailed comment on lispWindow ivar
+     explaining why staticpro is not needed (windows reachable from
+     frame tree, GC only on main thread, AX getters dispatch to main).
+
+  3. ns-accessibility-enabled (DEFVAR_BOOL): new user option to
+     disable accessibility entirely.  Guards three entry points.
+
+  4. postAccessibilityNotificationsForFrame: extracted from one ~200
+     line method into four focused helpers:
+     - postTextChangedNotification: (typing echo)
+     - postFocusedCursorNotification:direction:granularity:markActive:
+       oldMarkActive: (focused cursor/selection)
+     - postCompletionAnnouncementForBuffer:point: (completions)
+     - postAccessibilityNotificationsForFrame: (orchestrator, ~60 lines)
+
+  5. ns_ax_completion_text_for_span: added block_input/unblock_input
+     with specpdl unwind protection for signal safety.
+
+  6. Fplist_get third-argument comment (PREDICATE, not default value).
+
+  7. Documentation: macos.texi section updated with
+     ns-accessibility-enabled variable reference.  etc/NEWS updated.
+
+
 -- end of README --