v0.4.1

v0.4.1 — Fix asymmetric word-diff highlight position

Bug fix

• Fixed off-by-1 highlight position when diffWords produces asymmetric ranges
  (e.g. ref(L) → ref) showed word-level highlights on old side only).
  Skips word-diff emphasis when ranges are present on only one side.

Reliability

• injectBg re-asserts background after \x1b[39m (fg-reset) sequences
  — Shiki uses these between tokens instead of full reset \x1b[0m.

Closes #1