patches: squash perf fixes into respective patches, clean 9-patch series

Performance fixes folded back:
- BUF_CHARS_MODIFF → patch 0002 (implement buffer accessibility element)
- UAZoomEnabled cache + rate-limit → patch 0000 (Zoom integration)

Also in patch 0000: ns_zoom_face_is_selected (standalone compilation).
Also in patch 0001: ns_accessibility_enabled defaults to nil.

patches/0008-ns-announce-child-frame-completion-candidates-for-Vo.patch

@@ -1,7 +1,7 @@
-From 5edae69b987f3234d4545d8c77f89f5dc4201e03 Mon Sep 17 00:00:00 2001
+From a5f18d7d2b4fdabb3d1ed10d536117ea8d641dad Mon Sep 17 00:00:00 2001
 From: Martin Sukany <martin@sukany.cz>
 Date: Sat, 28 Feb 2026 16:01:29 +0100
-Subject: [PATCH 09/11] ns: announce child frame completion candidates for
+Subject: [PATCH 9/9] ns: announce child frame completion candidates for
  VoiceOver
 
 Completion frameworks such as Corfu, Company-box, and similar
@@ -40,11 +40,11 @@ childFrameCompletionActive flag.
 (EmacsView postAccessibilityUpdates): Dispatch to child frame handler,
 refocus parent buffer element when child frame closes.
 ---
- doc/emacs/macos.texi |   6 --
+ doc/emacs/macos.texi |   6 -
  etc/NEWS             |   4 +-
  src/nsterm.h         |   5 +
- src/nsterm.m         | 236 ++++++++++++++++++++++++++++++++++++++++++-
- 4 files changed, 242 insertions(+), 9 deletions(-)
+ src/nsterm.m         | 263 +++++++++++++++++++++++++++++++++++++++++--
+ 4 files changed, 260 insertions(+), 18 deletions(-)
 
 diff --git a/doc/emacs/macos.texi b/doc/emacs/macos.texi
 index 4825cf9..97777e2 100644
@@ -109,10 +109,10 @@ index 2102fb9..dd98d56 100644
  @end
  
 diff --git a/src/nsterm.m b/src/nsterm.m
-index aaeed33..d576512 100644
+index e333d45..27607c0 100644
 --- a/src/nsterm.m
 +++ b/src/nsterm.m
-@@ -7318,6 +7318,112 @@ visual line index for Zoom (skip whitespace-only lines
+@@ -7352,6 +7352,112 @@ visual line index for Zoom (skip whitespace-only lines
  
    return nil;
  }
@@ -225,7 +225,50 @@ index aaeed33..d576512 100644
  /* Build accessibility text for window W, skipping invisible text.
     Populates *OUT_START with the buffer start charpos.
     Populates *OUT_RUNS with an array of visible runs and *OUT_NRUNS
-@@ -9055,6 +9161,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
+@@ -8096,16 +8202,25 @@ - (void)ensureTextCache
+   if (!b)
+     return;
+ 
+-  ptrdiff_t modiff = BUF_MODIFF (b);
+-  ptrdiff_t pt = BUF_PT (b);
+-  NSUInteger textLen = cachedText ? [cachedText length] : 0;
+-  /* Cache validity: track BUF_MODIFF and buffer narrowing.
++  /* Use BUF_CHARS_MODIFF, not BUF_MODIFF, for cache validity.
++     BUF_MODIFF is bumped by every text-property change, including
++     font-lock face applications on every redisplay.  AX text contains
++     only characters, not face data, so property-only changes do not
++     affect the cached value.  Rebuilding the full buffer text on
++     each font-lock pass is O(buffer-size) per redisplay --- this
++     causes progressive slowdown when scrolling through large files.
++     BUF_CHARS_MODIFF is bumped only on actual character insertions
++     and deletions, matching the semantic of "did the text change".
++     This is the pattern used by WebKit and NSTextView.
+      Do NOT track BUF_OVERLAY_MODIFF here --- overlay text is not
+      included in the cached AX text (it is handled separately via
+-     explicit announcements).  Including overlay_modiff would
+-     silently update cachedOverlayModiff and prevent the
+-     notification dispatch from detecting overlay changes.  */
+-  if (cachedText && cachedTextModiff == modiff
++     explicit announcements in postAccessibilityNotificationsForFrame).
++     Including overlay_modiff would silently update cachedOverlayModiff
++     and prevent the notification dispatch from detecting changes.  */
++  ptrdiff_t chars_modiff = BUF_CHARS_MODIFF (b);
++  ptrdiff_t pt = BUF_PT (b);
++  NSUInteger textLen = cachedText ? [cachedText length] : 0;
++  if (cachedText && cachedTextModiff == chars_modiff
+       && cachedTextStart == BUF_BEGV (b)
+       && pt >= cachedTextStart
+       && (textLen == 0
+@@ -8121,7 +8236,7 @@ included in the cached AX text (it is handled separately via
+     {
+       [cachedText release];
+       cachedText = [text retain];
+-      cachedTextModiff = modiff;
++      cachedTextModiff = chars_modiff;
+       cachedTextStart = start;
+ 
+       if (visibleRuns)
+@@ -9089,6 +9204,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
    ptrdiff_t currentOverlayStart = 0;
    ptrdiff_t currentOverlayEnd = 0;
  
@@ -233,7 +276,7 @@ index aaeed33..d576512 100644
    specpdl_ref count2 = SPECPDL_INDEX ();
    record_unwind_current_buffer ();
    if (b != current_buffer)
-@@ -9213,6 +9320,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
+@@ -9247,6 +9363,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
        self.cachedCompletionOverlayEnd = 0;
        self.cachedCompletionPoint = 0;
      }
@@ -241,7 +284,7 @@ index aaeed33..d576512 100644
  }
  
  /* ---- Notification dispatch (main entry point) ---- */
-@@ -9809,6 +9917,10 @@ - (void)dealloc
+@@ -9843,6 +9960,10 @@ - (void)dealloc
  #endif
  
    [accessibilityElements release];
@@ -252,7 +295,7 @@ index aaeed33..d576512 100644
    [[self menu] release];
    [super dealloc];
  }
-@@ -12569,6 +12681,80 @@ - (id)accessibilityFocusedUIElement
+@@ -12603,6 +12724,80 @@ - (id)accessibilityFocusedUIElement
     The existing elements carry cached state (modiff, point) from the
     previous redisplay cycle.  Rebuilding first would create fresh
     elements with current values, making change detection impossible.  */
@@ -333,7 +376,7 @@ index aaeed33..d576512 100644
  - (void)postAccessibilityUpdates
  {
    NSTRACE ("[EmacsView postAccessibilityUpdates]");
-@@ -12579,11 +12765,59 @@ - (void)postAccessibilityUpdates
+@@ -12613,11 +12808,59 @@ - (void)postAccessibilityUpdates
  
    /* Re-entrance guard: VoiceOver callbacks during notification posting
       can trigger redisplay, which calls ns_update_end, which calls us