fix: Handle cursor change events with NotSet reason in setupCursorExplicitPosChangeCallback

[coderabbitai]

Background

When using keyboard shortcuts (CTRL + U/I) to navigate to the top/bottom of the page, the log event number is not updated. This is because setPosition only allows specifying a source but not a reason for the cursor change event, resulting in NotSet reason.

Current Behavior

• Keyboard shortcuts CTRL + U/I navigate to top/bottom of page
• Log event number in URL doesn't update
• Cursor change event has NotSet reason when using setPosition

Proposed Solution

Modify setupCursorExplicitPosChangeCallback to check for NotSet reason in addition to Explicit reason, as setPosition is currently the only way to trigger a cursor change event with NotSet reason.

References

• Related PR: fix(logEventNum): Keyboard navigation shortcuts should update the log event number (fixes #105). #180

[junhaoliao]

This is a duplicate of #105