patches: review pass 3 - move block_input to origin patches

block_input protection moved from P0008 to their respective origin
patches for independent compilability (GNU Emacs requirement):
- P0001 (ns_ax_buffer_text): now has block_input + record_unwind
- P0003 (postCompletionAnnouncementForBuffer): now has block_input
- P0004 (ns_ax_scan_interactive_spans): now has block_input

P0008 now only adds its own new functionality (child frame completion
announcements, echo area announcements) without duplicating block_input
from earlier patches.

All 9 patches apply cleanly with git am on Linux git 2.43.0.

patches/0004-ns-add-interactive-span-elements-for-Tab-navigation.patch

@@ -1,7 +1,7 @@
-From e3c3878e65d8273e5fca97e942fe97ff3c5c113f Mon Sep 17 00:00:00 2001
+From 589f1536255d1ad28552d8047387fbf3e9288235 Mon Sep 17 00:00:00 2001
 From: Martin Sukany <martin@sukany.cz>
 Date: Sat, 28 Feb 2026 12:58:11 +0100
-Subject: [PATCH 5/9] ns: add interactive span elements for Tab navigation
+Subject: [PATCH 4/8] ns: add interactive span elements for Tab navigation
 
 * src/nsterm.m (ns_ax_scan_interactive_spans): New function; scans the
 visible portion of a buffer for interactive text properties
@@ -14,14 +14,14 @@ elements with an AXPress action that sends a synthetic TAB keystroke.
 (accessibilityChildrenInNavigationOrder): Return cached span array,
 rebuilding lazily when interactiveSpansDirty is set.
 ---
- src/nsterm.m | 287 +++++++++++++++++++++++++++++++++++++++++++++++++++
- 1 file changed, 287 insertions(+)
+ src/nsterm.m | 291 +++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 291 insertions(+)
 
 diff --git a/src/nsterm.m b/src/nsterm.m
-index cbf29694dd..e8bbc1ffe1 100644
+index 9e0e317237..b460beb00c 100644
 --- a/src/nsterm.m
 +++ b/src/nsterm.m
-@@ -9342,6 +9342,293 @@ - (NSRect)accessibilityFrame
+@@ -9346,6 +9346,297 @@ - (NSRect)accessibilityFrame
  
  @end
  
@@ -57,6 +57,10 @@ index cbf29694dd..e8bbc1ffe1 100644
 +  if (vis_start >= vis_end)
 +    return @[];
 +
++  block_input ();
++  specpdl_ref blk_count = SPECPDL_INDEX ();
++  record_unwind_protect_void (unblock_input);
++
 +  /* Symbols are interned once at startup via DEFSYM in syms_of_nsterm;
 +     reference them directly here (GC-safe, no repeated obarray lookup).  */
 +