fix: hide images when org headings are collapsed

Add fold-aware visibility detection so images disappear when their
containing heading is folded and reappear when expanded.

- Add kitty-gfx--in-folded-region-p: checks org-fold (9.6+) then
  falls back to overlay-based invisibility, ignoring cosmetic
  org-link bracket hiding
- Update kitty-gfx--overlay-screen-pos to skip folded overlays
- Add kitty-gfx--on-org-cycle hook: deletes terminal placements
  before clearing cache, then schedules refresh

0 files changed, 0 insertions, 0 deletions