v1.20.0

Added

• Word-jump cursor keys. The viewer's horizontal cursor now
  honours macOS-standard chords plus vim word motions:

  • Option+Left / Option+Right (Alt+Left/Right on Linux) — jump
    by whitespace-separated word.
  • Home / End (Cmd+Left / Cmd+Right via Terminal.app forwarding)
    — jump to line start / end.
  • w — next word; b — previous word; e — same as
    w for now (the viewer has no "yank to end of word" so the two
    semantics collapse).
  • ^ — line start; $ — line end.

  Visual mode (v) extends the selection through word jumps too, so
  Option+Right after v selects a word at a time.

  Word definition is the simple "maximal run of non-whitespace"
  segmentation — same as terminal readline and most editors'
  default. Indexed by char position; multi-byte / wide chars (CJK,
  emoji) get the same approximation as the existing single-cell
  h/l arrows.

  Covered by 7 unit tests on next_word_col / prev_word_col.