fix: stabilize Live Activity infinite scroll pagination

[nickmopen]

Summary

Fixes the Live Activity infinite scroll on the Dashboard that would enter an endless loading loop when scrolling at a moderate pace.

Note: This PR addresses Issue 1 (infinite scroll) from #685. Issue 2 (repo table chart showing incorrect bar heights / empty bars when sorting by Weight with Log Scale enabled) was investigated but could not be reproduced — the chart behaved correctly under all tested conditions (ascending, descending, log scale on/off). No changes were made for Issue 2.

Two root causes addressed for Issue 1:

• DashboardApi: getNextPageParam was using allPages.length + 1 to derive the next page number. During a background refetchInterval refetch, allPages is rebuilt page-by-page and can be shorter than expected when getNextPageParam is evaluated, causing a stale/incorrect page number to be requested. Changed to lastPageParam + 1 which is always the canonical value.

• LiveCommitLog: The IntersectionObserver had isFetchingNextPage and visibleEntries.length in its dependency array. Every time a page loaded, the effect would teardown and recreate the observer — which would immediately fire if the sentinel element was still in the viewport, bypassing the in-flight guard and triggering another fetchNextPage(). This created the infinite request loop. Replaced with a debounced scroll handler (120ms) that checks a fixed pixel distance from the bottom of the container, with a fetchInFlightRef flag to prevent concurrent fetches. Removes the sentinel DOM element entirely.

Related Issues

See #685 (Issue 1 only — Issue 2 not reproducible, no changes made)

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other (describe below)

Screenshots

before

Screen.Recording.2026-05-11.at.8.30.27.PM.mov

after

Screen.Recording.2026-05-11.at.8.29.46.PM.mov

Checklist

• New components are modularized/separated where sensible
• Uses predefined theme (e.g. no hardcoded colors)
• Responsive/mobile checked
• Tested against the test API
• npm run format and npm run lint:fix have been run
• npm run build passes
• Screenshots included for any UI/visual changes

[anderdc]

Three things to address before merge:

• src/pages/dashboard/views/LiveCommitLog.tsx: the scrollDebounceRef timeout is never cleared on unmount. Add a cleanup effect that clears the pending timeout.
• LiveCommitLog.tsx: the scroll handler only fires on a real scroll event, so if the first page doesn't fill the container there's nothing to trigger fetchNextPage and more pages can't load. Handle the not-scrollable case — the IntersectionObserver this replaces covered it automatically.
• PR body: "Fixes #685" will auto-close the issue on merge while Issue 2 (repo bar chart) is still unaddressed. Reference #685 without the closing keyword so it stays open for Issue 2.