sync.ts: after computing standings from played matches, seed 0-0-0-0 rows
for every team in any group match, so all 12 groups always appear.
/groups: fetch all 2026 matches alongside standings; each group card now
shows results (score), live badge, and upcoming fixtures with local
kickoff time, sorted by UTC kickoff.
/tournaments/[year]: derive group list from union of standings + match
group names, so groups with no played matches still render with their
fixtures.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>