Method captureScrolledRows

src/ink/ink.tsx:1157–1159

* Capture text from rows about to scroll out of the viewport during * drag-to-scroll. Must be called BEFORE the ScrollBox scrolls so the * screen buffer still holds the outgoing content. Accumulated into * the selection state and joined back in by getSelectedText.

(firstRow: number, lastRow: number, side: 'above' | 'below')

   * the selection state and joined back in by getSelectedText.
   */
  captureScrolledRows(firstRow: number, lastRow: number, side: 'above' | 'below'): void {
    captureScrolledRows(this.selection, this.frontFrame.screen, firstRow, lastRow, side);
  }

  /**
   * Shift anchor AND focus by dRow, clamped to [minRow, maxRow]. Used by