feat: add local fixture pricing provider

apps/api/tests/application/pricing-provider.test.js

@@ -2,6 +2,7 @@ import assert from 'node:assert/strict';
 import test from 'node:test';
 
 import { createPricingProvider, createPricingProviderRegistry } from '../../src/modules/pricing/providers/pricing-provider.js';
+import { createFixturePricingProvider } from '../../src/modules/pricing/providers/fixture-pricing-provider.js';
 
 test('registers pricing providers behind a validated adapter contract', async () => {
   const provider = createPricingProvider({
@@ -19,4 +20,19 @@ test('rejects malformed provider adapters and responses', async () => {
   assert.throws(() => createPricingProvider({ id: 'broken' }), /observe function is required/);
   const provider = createPricingProvider({ id: 'broken', async observe() { return null; } });
   await assert.rejects(() => provider.observe({}), /must return an observation array/);
+});
+
+test('fixture provider returns deterministic normalized observations', async () => {
+  const [observation] = await createFixturePricingProvider().observe({
+    productId: 'product-1', inventoryItemId: 'item-1', conditionId: 'condition-1',
+  });
+  assert.deepEqual(observation, {
+    productId: 'product-1',
+    inventoryItemId: 'item-1',
+    conditionId: 'condition-1',
+    priceMinor: 2500,
+    currency: 'USD',
+    sourceIdentifier: 'fixture-item-1',
+    qualityScore: 50,
+  });
 });