FE: Boots/Tests comparison table

[alanpeixinho]

Summary

Display the row-level comparison table for boots and tests inside the comparison view.

Details

Table content

• Shows all rows where status_a ≠ status_b, including rows that ran on only one side (the other side is null)
• Columns: Path, Config, Platform, Side A status, Side B status

Filtering

• Filter by transition type: regressions (PASS→FAIL), fixes (FAIL→PASS), all changes, appeared/disappeared (null on one side)
• Same diffFilter applied to both sides before comparison

Grouping

• Groupable by path_group (first path segment ≈ suite), config, or platform
• Grouped view shows flip counts per group (e.g. "kselftest: 4 regressions, 1 fix")
• Expandable to see individual rows within a group

Empty state

• When no boots/tests differ, show the "no changes" state consistent with the comparison page

Notes

• Boots and tests share the identity key (path + config + platform) and the same table structure, so they use the same component under their respective tabs
• Status rendering reuses existing status badge components; a null side is rendered as a neutral/empty state (e.g. a dash)