feat: add pricing observation API

Add seller-owned pricing observation persistence, median market valuation calculation, admin routes, contracts, validation, migration, and focused tests.

apps/api/src/app/build-app.js

@@ -17,6 +17,7 @@ import { registerPublicSellerRoutes } from '../modules/sellers/routes/public-sel
 import { registerAdminSaleRoutes } from '../modules/sales/routes/admin-sale-routes.js';
 import { registerAdminAcquisitionRoutes } from '../modules/acquisitions/routes/admin-acquisition-routes.js';
 import { registerAdminDashboardRoutes } from '../modules/dashboard/routes/admin-dashboard-routes.js';
+import { registerAdminPricingRoutes } from '../modules/pricing/routes/admin-pricing-routes.js';
 
 export function buildApp(dependencies) {
   const app = Fastify();
@@ -76,6 +77,10 @@ export function buildApp(dependencies) {
     ...dependencies,
     prefix: '/api/v1/admin',
   });
+  app.register(registerAdminPricingRoutes, {
+    ...dependencies,
+    prefix: '/api/v1/admin',
+  });
   app.register(registerPublicSearchRoutes, {
     ...dependencies,
     prefix: '/api/v1',