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/domain/acquisition-pricing.test.js

@@ -8,6 +8,7 @@ import {
 import {
   calculateMedianPriceMinor,
   createPricingObservation,
+  identifyOutlierPrices,
 } from '../../src/modules/pricing/domain/pricing-observation.js';
 
 test('calculates acquisition cost basis from all cost components', () => {
@@ -57,3 +58,8 @@ test('creates pricing observations and calculates a median observed price', () =
   assert.equal(observation.priceMinor, 2499);
   assert.equal(calculateMedianPriceMinor([1199, 2499, 2000]), 2000);
 });
+
+test('identifies extreme pricing observations without discarding normal values', () => {
+  assert.deepEqual([...identifyOutlierPrices([1000, 1050, 1100, 5000])], [5000]);
+  assert.equal(identifyOutlierPrices([1000, 1050, 1100]).size, 0);
+});