feat: add pricing quality controls

Add robust outlier detection, stale valuation metadata, and audited seller-scoped market-value overrides with migration and tests.

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

@@ -10,6 +10,9 @@ test('records an owned pricing observation and calculates a valuation', async ()
         assert.equal(sellerId, 'seller-1');
         return { status: 'CREATED', observation };
       },
+      async markOutliersForSeller() {
+        return { status: 'UPDATED' };
+      },
       async calculateForSeller() {
         return { status: 'CALCULATED', valuation: { valueMinor: 2500 }, observations: [] };
       },
@@ -23,4 +26,12 @@ test('records an owned pricing observation and calculates a valuation', async ()
   assert.equal(observation.priceMinor, 2500);
   const valuation = await service.calculate({ sellerId: 'seller-1', inventoryItemId: 'inventory-1' });
   assert.equal(valuation.valuation.valueMinor, 2500);
+});
+
+test('requires a reason for an audited market-value override', async () => {
+  const service = createPricingService({ pricingRepository: { async createOverride() { throw new Error('should not run'); } } });
+  await assert.rejects(
+    () => service.override({ sellerId: 'seller-1', actorUserId: 'user-1', inventoryItemId: 'inventory-1', valueMinor: 2000, reason: 'x' }),
+    (error) => error.code === 'OVERRIDE_REASON_REQUIRED' && error.statusCode === 400,
+  );
 });