Add #/compare page that lets users select two observers and compare
which packets each sees. Fetches last 24h of packets per observer,
computes set diff client-side using O(n) Set lookups. Shows summary
cards (both/only-A/only-B), stacked bar, type breakdown, and tabbed
detail tables. URL is shareable via ?a=ID1&b=ID2 query params.
- New file: public/compare.js (comparePacketSets + page module)
- Added compare button to observers page header
- 11 new tests for comparePacketSets (87 total frontend tests)
- Cache busters bumped
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Kpa-clawbot
99c23f8b59
