Fix early-bird price blending and mislabeling; add contact-only events

- Early-bird pricing: RegistrationOption now tracks each purchase as a
  separate price tranche instead of overwriting a single price/quantity
  on repeat purchases, so buying more tickets after a tier expires no
  longer re-prices tickets already bought at the old price. Stock-limit
  checks, total-due calculation, and the Finance report's revenue-by-
  option are all tranche-aware; pages that showed one blended price per
  line now render/total each tranche. Viewing a pending/partially-paid
  registration (dashboard, detail page, or an event's registration
  list) now refreshes stale pricing on the spot instead of only at
  payment time.
- Fixed the "(early bird)" dashboard label incorrectly firing on any
  line priced below the base option price (e.g. a plain cheaper
  variant) — it now checks the real applied-tier flag.
- Added contact-only events (e.g. baptism): no registration/payment
  flow, shown on the public site with a "Contact us" popup instead of
  a Register button. Configurable via the admin event wizard.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/components/events/ContactButton.tsx

@@ -0,0 +1,72 @@
+"use client";
+
+import { useState } from "react";
+import { X, Phone, Mail, User } from "lucide-react";
+
+type ContactButtonProps = {
+  contactName?: string | null;
+  contactPhone?: string | null;
+  contactEmail?: string | null;
+  className?: string;
+  label?: string;
+};
+
+export function ContactButton({ contactName, contactPhone, contactEmail, className, label = "Contact us" }: ContactButtonProps) {
+  const [open, setOpen] = useState(false);
+  const hasDetails = !!(contactName || contactPhone || contactEmail);
+
+  return (
+    <>
+      <button
+        type="button"
+        onClick={() => setOpen(true)}
+        className={className || "flex-1 text-center text-sm text-white bg-brand-600 rounded-lg py-2 hover:bg-brand-700 transition-colors"}
+      >
+        {label}
+      </button>
+      {open && (
+        <div
+          className="fixed inset-0 bg-black/40 flex items-center justify-center z-50"
+          onClick={() => setOpen(false)}
+        >
+          <div className="bg-white rounded-lg shadow-lg max-w-sm w-full mx-4 p-5" onClick={e => e.stopPropagation()}>
+            <div className="flex items-center justify-between mb-3">
+              <h3 className="text-lg font-semibold">Contact us</h3>
+              <button
+                className="p-1 rounded hover:bg-gray-100 text-gray-500"
+                onClick={() => setOpen(false)}
+                aria-label="Close"
+              >
+                <X className="w-4 h-4" />
+              </button>
+            </div>
+            {hasDetails ? (
+              <div className="space-y-2 text-sm">
+                {contactName && (
+                  <div className="flex items-center gap-2 text-gray-800">
+                    <User className="w-4 h-4 text-gray-400 shrink-0" />
+                    <span>{contactName}</span>
+                  </div>
+                )}
+                {contactPhone && (
+                  <div className="flex items-center gap-2">
+                    <Phone className="w-4 h-4 text-gray-400 shrink-0" />
+                    <a href={`tel:${contactPhone}`} className="text-brand-600 hover:underline">{contactPhone}</a>
+                  </div>
+                )}
+                {contactEmail && (
+                  <div className="flex items-center gap-2">
+                    <Mail className="w-4 h-4 text-gray-400 shrink-0" />
+                    <a href={`mailto:${contactEmail}`} className="text-brand-600 hover:underline">{contactEmail}</a>
+                  </div>
+                )}
+              </div>
+            ) : (
+              <p className="text-sm text-gray-500">No contact details have been provided for this event.</p>
+            )}
+          </div>
+        </div>
+      )}
+    </>
+  );
+}

frontend/src/components/events/EventCard.tsx

@@ -1,5 +1,6 @@
 import { ApiImage } from "@/components/shared/ApiImage";
 import { Calendar } from "lucide-react";
+import { ContactButton } from "@/components/events/ContactButton";
 
  type Event = {
    id: string;
@@ -12,6 +13,10 @@ import { Calendar } from "lucide-react";
    price: number;
    picture?: string;
    isSoldOut?: boolean;
+   requiresRegistration?: boolean;
+   contactName?: string | null;
+   contactPhone?: string | null;
+   contactEmail?: string | null;
 };
 
 import { formatDateTimeRange } from "@/lib/date";
@@ -47,6 +52,15 @@ export const EventCard = ({ event }: { event: Event }) => {
                         View details
                     </a>
                     {(() => {
+                      if (event.requiresRegistration === false) {
+                        return (
+                          <ContactButton
+                            contactName={event.contactName}
+                            contactPhone={event.contactPhone}
+                            contactEmail={event.contactEmail}
+                          />
+                        );
+                      }
                       const now = new Date();
                       const end = new Date(event.endDate);
                       const deadline = event.registrationDeadline ? new Date(event.registrationDeadline) : null;