When moving up/down through lines of varying lengths, the editor now
remembers the original column position and restores it when reaching a
line long enough to accommodate it.
Example: cursor at column 10, move up to a shorter line (cursor clamps
to end), move up again to a longer line - cursor returns to column 10.
Implementation:
- Add preferredVisualCol instance property (nullable)
- Set it when moving to a shorter line during vertical navigation
- Clear it when arriving at a line that fits the preferred column
- Clear it on any horizontal movement or editing via setCursorCol()
- Detect line rewrap by checking if cursor is in middle of line
- When pressing right at end of prompt, set preferredVisualCol so
subsequent up/down navigation uses that column position
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