- Added prefetching in both terminal and GUI renderers to optimize visible row highlights.
- Introduced background worker for offscreen highlight warming to improve scrolling performance.
- Refactored `HighlighterEngine` to manage thread-safety, caching, and stateful re-computation.
- Integrated changes into `HighlighterEngine`, `TerminalRenderer`, and `GUIRenderer`.
- Bumped version to 1.2.0 in preparation for the release.