feat: add dynamic pricing tiers to CCG registration

Replace hardcoded €80 ticket price with date-based tiers:
- Early bird €80 (until Mar 31)
- Regular €120 (Apr 1 – Jun 30)
- Late €150 (Jul 1+)

Both the register page and checkout API now compute the current
tier at request time, so prices update automatically on cutoff dates.

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

app/api/create-checkout-session/route.ts

@@ -11,8 +11,19 @@ function getMollie() {
   return mollieClient
 }
 
-// Dynamic pricing configuration (in EUR)
+// Dynamic pricing tiers (in EUR)
-const TICKET_PRICE = 80 // €80 early bird
+const PRICING_TIERS = [
+  { label: "Early bird", price: 80, cutoff: "2026-03-31" },
+  { label: "Regular", price: 120, cutoff: "2026-07-01" },
+  { label: "Late", price: 150, cutoff: "2099-12-31" },
+]
+
+function getCurrentTicketPrice(): number {
+  const now = new Date().toISOString().slice(0, 10)
+  const tier = PRICING_TIERS.find((t) => now < t.cutoff) ?? PRICING_TIERS[PRICING_TIERS.length - 1]
+  return tier.price
+}
+
 const PROCESSING_FEE_PERCENT = 0.02 // 2% to cover Mollie payment processing fees
 
 // Accommodation prices per person for 7 nights
@@ -39,8 +50,9 @@ export async function POST(request: NextRequest) {
     const registrationData = registrationDataStr ? JSON.parse(registrationDataStr) : null
 
     // Calculate subtotal
-    let subtotal = TICKET_PRICE
+    const ticketPrice = getCurrentTicketPrice()
-    const descriptionParts = ["CCG 2026 Ticket (€80)"]
+    let subtotal = ticketPrice
+    const descriptionParts = [`CCG 2026 Ticket (€${ticketPrice})`]
 
     if (includeAccommodation) {
       const accom = ACCOMMODATION_PRICES[accommodationType]

app/register/page.tsx

@@ -30,7 +30,15 @@ export default function RegisterPage() {
     dietaryOther: "",
     crewConsent: "",
   })
-  const baseTicketPrice = 80 // Early bird price €80
+  // Dynamic pricing tiers
+  const pricingTiers = [
+    { label: "Early bird", price: 80, cutoff: "2026-03-31" },
+    { label: "Regular", price: 120, cutoff: "2026-07-01" },
+    { label: "Late", price: 150, cutoff: "2099-12-31" },
+  ]
+  const now = new Date().toISOString().slice(0, 10)
+  const currentTier = pricingTiers.find((t) => now < t.cutoff) ?? pricingTiers[pricingTiers.length - 1]
+  const baseTicketPrice = currentTier.price
 
   const accommodationPrices: Record<string, { label: string; price: number }> = {
     "ch-multi": { label: "Bed in shared room (Commons Hub)", price: 279.30 },
@@ -133,7 +141,7 @@ export default function RegisterPage() {
             <CardHeader>
               <CardTitle>Event Registration</CardTitle>
               <CardDescription>
-                Early bird pricing available until March 31, 2026
+                {currentTier.label} pricing — €{currentTier.price}
               </CardDescription>
             </CardHeader>
             <CardContent>
@@ -143,7 +151,9 @@ export default function RegisterPage() {
                   <div>
                     <div className="font-medium">CCG 2026 Ticket</div>
                     <div className="text-sm text-muted-foreground">
-                      €80 Early bird (until Mar 31) · €120 Regular (Apr-Jun) · €150 Late (after Jul 1)
+                      {pricingTiers.map((t, i) => (
+                        <span key={t.label}>{i > 0 ? " · " : ""}€{t.price} {t.label}{t === currentTier ? " (current)" : ""}</span>
+                      ))}
                     </div>
                     <div className="text-xs text-muted-foreground mt-1">
                       CCA members: Bring two newcomers, get a free ticket!