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

@@ -1,4 +1,4 @@
-From a75ee6aff3734bd053865b3df734b75642f7305e Mon Sep 17 00:00:00 2001
+From 5edae69b987f3234d4545d8c77f89f5dc4201e03 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
@@ -109,10 +109,10 @@ index 2102fb9..dd98d56 100644
  @end
  
 diff --git a/src/nsterm.m b/src/nsterm.m
-index 7c44e9c..12c451b 100644
+index aaeed33..d576512 100644
 --- a/src/nsterm.m
 +++ b/src/nsterm.m
-@@ -7298,6 +7298,112 @@ visual line index for Zoom (skip whitespace-only lines
+@@ -7318,6 +7318,112 @@ visual line index for Zoom (skip whitespace-only lines
  
    return nil;
  }
@@ -225,7 +225,7 @@ index 7c44e9c..12c451b 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
-@@ -9035,6 +9141,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
+@@ -9055,6 +9161,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
    ptrdiff_t currentOverlayStart = 0;
    ptrdiff_t currentOverlayEnd = 0;
  
@@ -233,7 +233,7 @@ index 7c44e9c..12c451b 100644
    specpdl_ref count2 = SPECPDL_INDEX ();
    record_unwind_current_buffer ();
    if (b != current_buffer)
-@@ -9193,6 +9300,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
+@@ -9213,6 +9320,7 @@ - (void)postCompletionAnnouncementForBuffer:(struct buffer *)b
        self.cachedCompletionOverlayEnd = 0;
        self.cachedCompletionPoint = 0;
      }
@@ -241,7 +241,7 @@ index 7c44e9c..12c451b 100644
  }
  
  /* ---- Notification dispatch (main entry point) ---- */
-@@ -9789,6 +9897,10 @@ - (void)dealloc
+@@ -9809,6 +9917,10 @@ - (void)dealloc
  #endif
  
    [accessibilityElements release];
@@ -252,7 +252,7 @@ index 7c44e9c..12c451b 100644
    [[self menu] release];
    [super dealloc];
  }
-@@ -12549,6 +12661,80 @@ - (id)accessibilityFocusedUIElement
+@@ -12569,6 +12681,80 @@ - (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 +333,7 @@ index 7c44e9c..12c451b 100644
  - (void)postAccessibilityUpdates
  {
    NSTRACE ("[EmacsView postAccessibilityUpdates]");
-@@ -12559,11 +12745,59 @@ - (void)postAccessibilityUpdates
+@@ -12579,11 +12765,59 @@ - (void)postAccessibilityUpdates
  
    /* Re-entrance guard: VoiceOver callbacks during notification posting
       can trigger redisplay, which calls ns_update_end, which calls us