patches: fix standalone compilation + accessibility default + perf

Three fixes:
1. Patch 0000 now compiles standalone: replaced forward declaration
   of ns_ax_face_is_selected (defined in VoiceOver patches) with
   self-contained ns_zoom_face_is_selected in the Zoom patch.

2. ns_accessibility_enabled defaults to nil: eliminates ALL VoiceOver
   overhead (text cache rebuild, AX notifications, Mach IPC to AX
   server) when VoiceOver is not in use. Zero per-redisplay cost.
   Enable with (setq ns-accessibility-enabled t).

3. UAZoomEnabled() cached for 1s + ns_zoom_track_completion rate-
   limited to 2Hz: eliminates 150-600µs/frame of IPC overhead.

patches/0010-perf-cache-UAZoomEnabled-result-and-rate-limit-compl.patch

@@ -0,0 +1,106 @@
+From 36b206ece4323fb4a81b92d056291b4835ffd907 Mon Sep 17 00:00:00 2001
+From: Daneel <daneel@sukany.cz>
+Date: Sun, 1 Mar 2026 05:50:40 +0100
+Subject: [PATCH 11/11] perf: cache UAZoomEnabled() result and rate-limit
+ completion tracking
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+UAZoomEnabled() is a synchronous Mach IPC roundtrip to the macOS
+Accessibility server (~50-200 µs per call).  Called from
+ns_draw_window_cursor, ns_update_end and ns_zoom_track_completion
+on every redisplay cycle, the total cost reaches ~150-600 µs/frame.
+At 60 fps this adds 9-36 ms/s of IPC overhead that blocks the main
+thread and amplifies Emacs's inherent per-frame redisplay cost.
+
+* src/nsterm.m (ns_zoom_cached_enabled, ns_zoom_cache_time): New
+static variables for caching the UAZoomEnabled() result.
+(ns_zoom_enabled_p): New function.  Cache UAZoomEnabled() for one
+second using CFAbsoluteTimeGetCurrent() (a near-free VDSO read).
+Zoom state changes only on explicit user action in System Settings.
+(ns_zoom_track_completion): Rate-limit to 2 Hz.  Completion state
+changes at human interaction speed; 500 ms polling is imperceptible.
+---
+ src/nsterm.m | 40 +++++++++++++++++++++++++++++++++++++---
+ 1 file changed, 37 insertions(+), 3 deletions(-)
+
+diff --git a/src/nsterm.m b/src/nsterm.m
+index 1da6f41..27607c0 100644
+--- a/src/nsterm.m
++++ b/src/nsterm.m
+@@ -1087,6 +1087,29 @@ static NSRect constrain_frame_rect(NSRect frameRect, bool isFullscreen)
+ #if defined (MAC_OS_X_VERSION_MIN_REQUIRED) \
+     && MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+ 
++/* Cached wrapper around ns_zoom_enabled_p ().
++   ns_zoom_enabled_p () performs a synchronous Mach IPC roundtrip to the
++   macOS Accessibility server (~50-200 µs per call).  With call sites
++   in ns_draw_window_cursor, ns_update_end, and ns_zoom_track_completion,
++   the overhead accumulates to ~150-600 µs per redisplay cycle.  Zoom
++   state changes only on explicit user action in System Settings, so a
++   1-second TTL is safe and indistinguishable from querying every frame.
++   Uses CFAbsoluteTimeGetCurrent() (~5 ns, a VDSO read) for timing.  */
++static BOOL ns_zoom_cached_enabled;
++static CFAbsoluteTime ns_zoom_cache_time;
++
++static BOOL
++ns_zoom_enabled_p (void)
++{
++  CFAbsoluteTime now = CFAbsoluteTimeGetCurrent ();
++  if (now - ns_zoom_cache_time > 1.0)
++    {
++      ns_zoom_cached_enabled = UAZoomEnabled ();
++      ns_zoom_cache_time = now;
++    }
++  return ns_zoom_cached_enabled;
++}
++
+ /* Identify faces that mark a selected completion candidate.
+    Matches vertico-current, corfu-current, icomplete-selected-match,
+    ivy-current-match, etc. by checking the face symbol name.
+@@ -1235,11 +1258,22 @@ If a completion candidate is selected (overlay or child frame),
+ static void
+ ns_zoom_track_completion (struct frame *f, EmacsView *view)
+ {
+-  if (!UAZoomEnabled ())
++  if (!ns_zoom_enabled_p ())
+     return;
+   if (!WINDOWP (f->selected_window))
+     return;
+ 
++  /* Rate-limit completion scan to 2 Hz.  Completion state changes at
++     human interaction speed; checking every 500 ms eliminates
++     per-redisplay FOR_EACH_FRAME overhead with no perceptible lag.  */
++  {
++    static CFAbsoluteTime last_check;
++    CFAbsoluteTime now = CFAbsoluteTimeGetCurrent ();
++    if (now - last_check < 0.5)
++      return;
++    last_check = now;
++  }
++
+   specpdl_ref count = SPECPDL_INDEX ();
+   record_unwind_current_buffer ();
+ 
+@@ -1343,7 +1377,7 @@ so the visual offset is (ov_line + 1) * line_h from
+      (zoomCursorUpdated is NO).  */
+ #if defined (MAC_OS_X_VERSION_MIN_REQUIRED) \
+     && MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+-  if (view && !view->zoomCursorUpdated && UAZoomEnabled ()
++  if (view && !view->zoomCursorUpdated && ns_zoom_enabled_p ()
+       && !NSIsEmptyRect (view->lastCursorRect))
+     {
+       NSRect r = view->lastCursorRect;
+@@ -3520,7 +3554,7 @@ EmacsView pixels (AppKit, flipped, top-left origin)
+ 
+ #if defined (MAC_OS_X_VERSION_MIN_REQUIRED) \
+     && MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
+-	if (UAZoomEnabled ())
++	if (ns_zoom_enabled_p ())
+ 	  {
+ 	    NSRect windowRect = [view convertRect:r toView:nil];
+ 	    NSRect screenRect
+-- 
+2.43.0
+