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>

backend/src/controllers/paymentController.js

@@ -78,7 +78,7 @@ const createPayment = async (req, res) => {
       registration = await prisma.registration.findUnique({
         where: { id: registrationId },
         include: {
-          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
           payments: true,
           user: { select: { id: true } }
         }
@@ -134,7 +134,7 @@ const createPayment = async (req, res) => {
       registration = await prisma.registration.findUnique({
         where: { id: registrationId },
         include: {
-          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
           payments: true,
           user: { select: { id: true } }
         }
@@ -242,7 +242,8 @@ const createPayment = async (req, res) => {
         include: {
           registrationOptions: {
             include: {
-              eventOption: { include: { earlyBirdTiers: true } }
+              eventOption: { include: { earlyBirdTiers: true } },
+              tranches: true
             }
           },
           payments: true
@@ -641,7 +642,8 @@ const assignDonationToRegistration = async (req, res) => {
       include: {
         registrationOptions: {
           include: {
-            eventOption: { include: { earlyBirdTiers: true } }
+            eventOption: { include: { earlyBirdTiers: true } },
+            tranches: true
           }
         },
         payments: true
@@ -812,7 +814,7 @@ const unassignDonationFromRegistration = async (req, res) => {
     const registration = await prisma.registration.findUnique({
       where: { id: leg.registrationId },
       include: {
-        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
         payments: true
       }
     });
@@ -846,7 +848,7 @@ const unassignDonationFromRegistration = async (req, res) => {
     const updatedRegistration = await prisma.registration.findUnique({
       where: { id: leg.registrationId },
       include: {
-        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
         payments: true
       }
     });
@@ -903,6 +905,7 @@ async function createRegistrationCheckoutInternal(registrationId, userId, { succ
         include: {
           eventOption: { include: { earlyBirdTiers: true } },
           variant: true,
+          tranches: true,
         }
       },
       payments: true,
@@ -1017,7 +1020,7 @@ const createYocoCheckout = async (req, res) => {
         const freshReg = await prisma.registration.findUnique({
           where: { id: registrationId },
           include: {
-            registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+            registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
             payments: true
           }
         });
@@ -1040,6 +1043,7 @@ const createYocoCheckout = async (req, res) => {
               include: {
                 eventOption: { include: { earlyBirdTiers: true } },
                 variant: true,
+                tranches: true,
               }
             },
             payments: true,
@@ -1270,7 +1274,7 @@ const createRefund = async (req, res) => {
       const registration = await prisma.registration.findUnique({
       where: { id: linkRegistrationId },
       include: {
-        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+        registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
         payments: true,
         // Load tickets to check usage if needed
         _count: true
@@ -1324,7 +1328,7 @@ const createRefund = async (req, res) => {
       const registration = await prisma.registration.findUnique({
         where: { id: linkRegistrationId },
         include: {
-          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } } } },
+          registrationOptions: { include: { eventOption: { include: { earlyBirdTiers: true } }, tranches: true } },
           payments: true
         }
       });