feat(interests): CM-2 Part B — interest_berths price override (data + resolver)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/unit/services/interest-berths-price.test.ts

@@ -0,0 +1,32 @@
+import { describe, it, expect } from 'vitest';
+
+import { resolveBerthPriceForInterest } from '@/lib/services/interest-berths.service';
+
+describe('resolveBerthPriceForInterest', () => {
+  it('uses the override when present', () => {
+    expect(
+      resolveBerthPriceForInterest(
+        { priceOverride: '1000000', priceOverrideCurrency: 'EUR' },
+        { price: '3880800', priceCurrency: 'USD' },
+      ),
+    ).toEqual({ price: '1000000', currency: 'EUR' });
+  });
+
+  it('falls back to the base list price when no override', () => {
+    expect(
+      resolveBerthPriceForInterest(
+        { priceOverride: null, priceOverrideCurrency: null },
+        { price: '3880800', priceCurrency: 'USD' },
+      ),
+    ).toEqual({ price: '3880800', currency: 'USD' });
+  });
+
+  it('uses the base currency when the override currency is null', () => {
+    expect(
+      resolveBerthPriceForInterest(
+        { priceOverride: '900000', priceOverrideCurrency: null },
+        { price: '3880800', priceCurrency: 'USD' },
+      ),
+    ).toEqual({ price: '900000', currency: 'USD' });
+  });
+});