fix: parse Wikipedia 12h time format and sort upcoming matches with NULLS LAST

Wikipedia stores match times as "6:00 p.m." (1-digit hour) which didn't
match the \d{2}:\d{2} regex, producing NULL for those matches. Introduced
parseTime12h() to handle 1-2 digit hours + AM/PM and convert to 24h.
Also sort upcomingMatches by NULLS LAST so unscheduled games appear after
timed ones rather than first. Dropped "openfootball" data attribution.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/layout.tsx

@@ -37,7 +37,7 @@ export default function RootLayout({ children }: { children: React.ReactNode })
           <main className="pt-[60px] min-h-screen">{children}</main>
           <footer className="border-t mt-8" style={{ borderColor: 'rgba(34,197,94,0.08)' }}>
             <div className="max-w-[1200px] mx-auto px-7 py-6 flex flex-col sm:flex-row items-center justify-between gap-2 text-[11px] text-[#1a3a22]">
-              <span>© {new Date().getFullYear()} World Cup Statistics. Data via openfootball.</span>
+              <span>© {new Date().getFullYear()} World Cup Statistics.</span>
               <a href="https://dev.pivoine.art" target="_blank" rel="noopener noreferrer"
                 className="text-[#2a5c35] hover:text-[#22c55e] transition-colors">
                 dev.pivoine.art