feat: add weekday abbreviation to flight results table

Each date row now shows e.g. "WED 2026-04-01" — the 3-letter weekday
prefix is rendered in muted monospace before the date string.

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

flight-comparator/frontend/src/pages/ScanDetails.tsx

@@ -29,6 +29,9 @@ const formatPrice = (price?: number) =>
 const formatDate = (d: string) =>
   new Date(d).toLocaleDateString('en-GB', { day: 'numeric', month: 'short', year: 'numeric' });
 
+const WEEKDAYS = ['SUN', 'MON', 'TUE', 'WED', 'THU', 'FRI', 'SAT'];
+const weekday = (d: string) => WEEKDAYS[new Date(d).getDay()];
+
 export default function ScanDetails() {
   const { id } = useParams<{ id: string }>();
   const navigate = useNavigate();
@@ -383,7 +386,10 @@ export default function ScanDetails() {
                                     <tbody className="divide-y divide-[#D4EDDA]">
                                       {(flightsByDest[route.destination] || []).map((f) => (
                                         <tr key={f.id} className="hover:bg-[#EEF7F0] transition-colors">
-                                          <td className="pl-12 pr-4 py-2.5 text-sm text-on-surface">{f.date}</td>
+                                          <td className="pl-12 pr-4 py-2.5 text-sm text-on-surface">
+                                            <span className="font-mono text-xs font-semibold text-on-surface-variant mr-2">{weekday(f.date)}</span>
+                                            {f.date}
+                                          </td>
                                           <td className="px-4 py-2.5 text-sm text-on-surface-variant">{f.airline || '—'}</td>
                                           <td className="px-4 py-2.5 text-sm text-on-surface-variant font-mono">{f.departure_time || '—'}</td>
                                           <td className="px-4 py-2.5 text-sm text-on-surface-variant font-mono">{f.arrival_time || '—'}</td>