v0.1.6

feat: v0.1.6 - Top bar + flicker fix + UI improvements

- Top bar showing file size and name, clickable to open file browser
- Shared terminal between file browser and hex viewer (no flicker)
- Help text moved to help.txt (include_str!)
- Help scrollbar draggable
- File browser: click again to open (touch-friendly)
- File browser: mouse click and scroll wheel support
- Selection: sp(18) bug fixed (start byte now highlights)