Feature request: Line Overlap and Visual Marker to PgUp/PgDn Scrolling #3003

I think it'd be nice if PgUp/PgDn will give some overlap for context retention, plus optional visual marker at overlap boundary if possible.

I'm interacting with OpenCode in android termux (ssh'd into a remote machine), where the letters are tiny and the screen is vertically long, and pgup/pgdn are the primary means of scrolling.

• Scroll by (screen height - N lines) on PgDn (overlap at top) and PgUp (overlap at bottom).
• N adjustable (0-10 lines) in settings.
• Super nice to have: Toggleable marker (e.g., faint line or highlight).

Current Behavior: Full-screen scroll with no overlap or marker.