1. setAccessibilitySelectedTextRange: — enables bidirectional cursor
sync. Converts AX index to buffer charpos, moves point via
SET_PT_BOTH. VoiceOver can now place cursor in text interaction mode.
2. setAccessibilityFocused: — handles VO+Shift+Down interaction entry.
Ensures NS window focus, posts SelectedTextChanged so VoiceOver
reads current line.
3. Completions announcement — when point changes in a non-focused
buffer (e.g. *Completions* during Tab), posts
AnnouncementRequestedNotification with the current line text.
VoiceOver speaks the selected completion while minibuffer keeps focus.
Daneel
31e452ed5c