patches: address maintainer review findings (C1/C2/H1/H2/M5/M6)

C1 - block_input ordering in ns_ax_buffer_text:
block_input() now called before record_unwind_protect_void(unblock_input).
Previously the unwind handler could have been called without a matching
block_input, corrupting the input-blocking reference count.

C2 - unbind_to missing in patch 0004:
unbind_to(blk_count, Qnil) moved from patch 0008 to patch 0004 so that
ns_ax_scan_interactive_spans has a complete block_input/unbind_to pair
when patches 0000-0004 are applied independently.

H1 - Zoom patch forward dependency on VoiceOver:
Removed forward declaration 'static bool ns_ax_face_is_selected' and
the delegation from ns_zoom_face_is_selected.  Restored standalone
implementation of ns_zoom_face_is_selected in the Zoom patch so patch
0000 compiles and links independently of the VoiceOver patches.

H2 - ns_accessibility_enabled removal undocumented:
Added comment to ns_zoom_track_completion explaining that Zoom cursor
tracking is gated only on ns_zoom_enabled_p(), not ns_accessibility_enabled.
Users running Zoom without VoiceOver must still get completion tracking.

M5 - childFrameLastBuffer GC safety undocumented:
Added comment at the assignment site explaining why BVAR(b, name) (an
interned symbol reachable from obarray) is GC-safe without staticpro.

M6 - FOR_EACH_FRAME without block_input:
Added block_input/unblock_input around the FOR_EACH_FRAME loop in
postAccessibilityUpdates that checks for visible child frames.
Vframe_list must not be modified by timers or process sentinels
during iteration.

patches/0005-ns-integrate-accessibility-with-EmacsView-and-redisp.patch

@@ -1,4 +1,4 @@
-From 31d94ecffbfc42a48c6222a1794b823fd0db7b3c Mon Sep 17 00:00:00 2001
+From 3a01e0c261a7ece2e8330dce32d4be6d5036be13 Mon Sep 17 00:00:00 2001
 From: Martin Sukany <martin@sukany.cz>
 Date: Sat, 28 Feb 2026 12:58:11 +0100
 Subject: [PATCH 5/8] ns: integrate accessibility with EmacsView and redisplay
@@ -51,7 +51,7 @@ index 4c149e41d6..7f917f93b2 100644
  ** Re-introduced dictation, lost in Emacs v30 (macOS).
  We lost macOS dictation in v30 when migrating to NSTextInputClient.
 diff --git a/src/nsterm.m b/src/nsterm.m
-index b460beb00c..7c118045bd 100644
+index 8aa5b6ac1b..32eb04acef 100644
 --- a/src/nsterm.m
 +++ b/src/nsterm.m
 @@ -1275,7 +1275,7 @@ If a completion candidate is selected (overlay or child frame),
@@ -224,7 +224,7 @@ index b460beb00c..7c118045bd 100644
  /* ===================================================================
     EmacsAccessibilityInteractiveSpan --- helpers and implementation
     =================================================================== */
-@@ -9682,6 +9774,7 @@ - (void)dealloc
+@@ -9683,6 +9775,7 @@ - (void)dealloc
    [layer release];
  #endif
  
@@ -232,7 +232,7 @@ index b460beb00c..7c118045bd 100644
    [[self menu] release];
    [super dealloc];
  }
-@@ -11030,6 +11123,32 @@ - (void)windowDidBecomeKey      /* for direct calls */
+@@ -11031,6 +11124,32 @@ - (void)windowDidBecomeKey      /* for direct calls */
    XSETFRAME (event.frame_or_window, emacsframe);
    kbd_buffer_store_event (&event);
    ns_send_appdefined (-1);  // Kick main loop
@@ -265,7 +265,7 @@ index b460beb00c..7c118045bd 100644
  }
  
  
-@@ -12267,6 +12386,332 @@ - (int) fullscreenState
+@@ -12268,6 +12387,332 @@ - (int) fullscreenState
    return fs_state;
  }
  
@@ -598,7 +598,7 @@ index b460beb00c..7c118045bd 100644
  @end  /* EmacsView */
  
  
-@@ -14263,12 +14708,17 @@ Nil means use fullscreen the old (< 10.7) way.  The old way works better with
+@@ -14264,12 +14709,17 @@ Nil means use fullscreen the old (< 10.7) way.  The old way works better with
    ns_use_srgb_colorspace = YES;
  
    DEFVAR_BOOL ("ns-accessibility-enabled", ns_accessibility_enabled,