Progress Bar: Connecting line does not connect conditionally shown pages

[JaneSjs]

T26223 - sd-progress-buttons__connector styling issue
https://surveyjs.answerdesk.io/internal/ticket/details/T26223

[mehran89]

Band aid fix:
When a new page becomes visible, the progress bar connector lines do not recalc their positions. SurveyJS only updates the connectors when the container width changes. To force a recalculation, I temporarily nudge the element's width by a tiny amount (+0.1px) and then revert it in the next animation frame. This is done inside the onPageVisibleChanged event, which fires when a page becomes visible. This triggers a layout recalculation without causing visible flicker. I also guard against multiple simultaneous nudges to prevent race conditions.