feat: add scatter-plot timeline view for config changes

[moshloop]

Summary

• Adds a Graph/Table toggle to the config changes view using reaviz ScatterPlot
• Changes are plotted by time (x-axis) and config name (y-axis) with tooltips showing change details
• Clicking a point in the graph opens the change detail modal
• Toggle state persists in localStorage via jotai atomWithStorage

Rebases the work from #2355 onto current main with minimal changes (Option A: keeps ConfigChangeTable's internal modal handling intact).

Test plan

• Navigate to a config detail's Changes tab
• Verify the Table/Graph toggle appears in the filter bar
• Toggle to Graph view — scatter plot renders with config changes
• Hover over a point — tooltip shows config name, change type, age, and summary
• Click a point — change detail modal opens
• Toggle back to Table view — table renders and row click modal still works
• Refresh page — toggle state persists

Summary by CodeRabbit

• New Features

  • Toggleable Table/Graph view for configuration changes with interactive graph points that open detail modals.
  • Artifacts area: summary cards, searchable/sortable table, preview modal with inline previews and downloads.
  • Optional Basic authentication flow with a simple login experience.

• Enhancements

  • Improved artifact download/preview handling for large and small files.
  • More consistent and richer error reporting surfaced via toasts.