feat: hide parks with no open days in the current week

Header subtitle now shows "X of 24 parks open" for context.

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

app/page.tsx

@@ -45,6 +45,11 @@ export default async function HomePage({ searchParams }: PageProps) {
     0
   );
 
+  // Only show parks that have at least one open day this week
+  const visibleParks = PARKS.filter((park) =>
+    weekDates.some((date) => data[park.id]?.[date]?.isOpen)
+  );
+
   return (
     <div style={{ minHeight: "100vh", background: "var(--color-bg)" }}>
       {/* Header */}
@@ -65,7 +70,7 @@ export default async function HomePage({ searchParams }: PageProps) {
             Six Flags Calendar
           </span>
           <span style={{ fontSize: "0.75rem", color: "var(--color-text-muted)" }}>
-            {PARKS.length} parks
+            {visibleParks.length} of {PARKS.length} parks open
           </span>
         </div>
 
@@ -79,7 +84,7 @@ export default async function HomePage({ searchParams }: PageProps) {
         {scrapedCount === 0 ? (
           <EmptyState />
         ) : (
-          <WeekCalendar parks={PARKS} weekDates={weekDates} data={data} />
+          <WeekCalendar parks={visibleParks} weekDates={weekDates} data={data} />
         )}
       </main>
     </div>