fix: add missing 'static BOOL' return type to ns_ax_find_completion_overlay_range

The function definition lacked a return type, causing:
  nsterm.m:7149:1: error: a type specifier is required for all declarations

Added 'static BOOL' — the function returns YES/NO and is file-scoped.
Updated patch line counts in header and README accordingly.

patches/0001-ns-implement-AXBoundsForRange-for-macOS-Zoom-cursor-.patch

@@ -85,8 +85,8 @@ Lisp calls, read only immutable NSString and scalar cache).
 ---
  etc/NEWS     |   11 +
  src/nsterm.h |  108 ++
- src/nsterm.m | 2869 +++++++++++++++++++++++++++++++++++++++++++++++---
- 3 files changed, 2840 insertions(+), 148 deletions(-)
+ src/nsterm.m | 2870 +++++++++++++++++++++++++++++++++++++++++++++++---
+ 3 files changed, 2841 insertions(+), 148 deletions(-)
 
 diff --git a/etc/NEWS b/etc/NEWS
 index 7367e3cc..0e4480ad 100644
@@ -640,6 +640,7 @@ index 932d209f..ea2de6f2 100644
 +  ns_ax_text_selection_granularity_line = 3,
 +};
 +
++static BOOL
 +ns_ax_find_completion_overlay_range (struct buffer *b, ptrdiff_t point,
 +				     ptrdiff_t *out_start,
 +				     ptrdiff_t *out_end)