Merge branch 'alpha' of github.com:Tria-plc/edr-platform into alpha

apps/edr-passenger-api/src/modules/payments/payment-client.service.ts

@@ -1,6 +1,7 @@
 import {
   BadGatewayException,
   BadRequestException,
+  ConflictException,
   Injectable,
   Logger,
 } from "@nestjs/common";
@@ -154,11 +155,16 @@ export class PaymentClientService {
     } catch (err) {
       if (err instanceof AxiosError && err.response) {
         // 4xx/5xx from the payment service: propagate 404 to callers that handle it;
-        // everything else is a gateway-level failure from the client's perspective.
+        // 409 = a legitimate conflict (e.g. another provider's payment is already in
+        // flight for this booking) — surface its message as-is rather than masking it as
+        // a gateway failure; everything else is a genuine gateway-level failure.
         if (err.response.status === 404) throw err;
         const detail =
           (err.response.data as { message?: string | string[] })?.message ??
           err.message;
+        if (err.response.status === 409) {
+          throw new ConflictException(detail);
+        }
         this.logger.error(
           `payment service ${method} ${path} → ${err.response.status}: ${detail}`,
         );

apps/edr-passenger-api/src/modules/payments/payments.service.ts

@@ -1072,6 +1072,19 @@ export class PaymentsService {
       return { processed: false, reason: "booking-not-found" };
     }
 
+    // C-4 guard: a settlement must cover what the passenger was quoted. Compare the provider-settled
+    // amount against the booking's display-currency total (the amount the customer agreed to pay);
+    // a short payment must NOT confirm the booking. Amount-only — the display↔charge currency
+    // divergence is tracked separately under the USD/DJF findings. The 1% tolerance absorbs rounding.
+    const expectedMinor = booking.displayTotalMinor ?? booking.totalMinor;
+    const shortPayTolerance = Math.max(1, Math.round(expectedMinor * 0.01));
+    if (event.amountMinor < expectedMinor - shortPayTolerance) {
+      this.logger.error(
+        `mark-paid: short payment for booking ${booking.id} — settled ${event.amountMinor} ${event.currency} < expected ${expectedMinor} ${booking.displayCurrency}; not confirming`,
+      );
+      return { processed: false, reason: "amount-mismatch" };
+    }
+
     // Local intent row is a projection during the strangler migration: reuse it when the
     // legacy initiate path created one, otherwise materialize it from the event.
     let intent = await this.prisma.paymentIntent.findUnique({