feat(specials): add launch and end dates for scheduling

app/special/[name]/page.tsx

@@ -14,10 +14,45 @@ interface PageProps {
 export default async function SpecialPage({ params }: PageProps) {
     const { name } = await params;
     const decodedName = decodeURIComponent(name);
+
+    const currentSpecial = await prisma.special.findUnique({
+        where: { name: decodedName }
+    });
+
+    const now = new Date();
+    const isStarted = currentSpecial && (!currentSpecial.launchDate || currentSpecial.launchDate <= now);
+    const isEnded = currentSpecial && (currentSpecial.endDate && currentSpecial.endDate < now);
+
+    if (!currentSpecial || !isStarted) {
+        return (
+            <div style={{ textAlign: 'center', padding: '2rem' }}>
+                <h1>Special Not Available</h1>
+                <p>This special has not launched yet or does not exist.</p>
+                <Link href="/">Go Home</Link>
+            </div>
+        );
+    }
+
+    if (isEnded) {
+        return (
+            <div style={{ textAlign: 'center', padding: '2rem' }}>
+                <h1>Special Ended</h1>
+                <p>This special event has ended.</p>
+                <Link href="/">Go Home</Link>
+            </div>
+        );
+    }
+
     const dailyPuzzle = await getOrCreateSpecialPuzzle(decodedName);
     const genres = await prisma.genre.findMany({ orderBy: { name: 'asc' } });
     const specials = await prisma.special.findMany({ orderBy: { name: 'asc' } });
 
+    const activeSpecials = specials.filter(s => {
+        const sStarted = !s.launchDate || s.launchDate <= now;
+        const sEnded = s.endDate && s.endDate < now;
+        return sStarted && !sEnded;
+    });
+
     return (
         <>
             <div style={{ textAlign: 'center', padding: '1rem', background: '#fce7f3' }}>
@@ -39,12 +74,12 @@ export default async function SpecialPage({ params }: PageProps) {
                     ))}
 
                     {/* Separator if both exist */}
-                    {genres.length > 0 && specials.length > 0 && (
+                    {genres.length > 0 && activeSpecials.length > 0 && (
                         <span style={{ color: '#d1d5db' }}>|</span>
                     )}
 
                     {/* Specials */}
-                    {specials.map(s => (
+                    {activeSpecials.map(s => (
                         <Link
                             key={s.id}
                             href={`/special/${s.name}`}