feat(listings): enrich GET /listings/:id with AVM, agent quality score, and similar count

- ListingDetailData: add valuationEstimate (AVM, cached 24 h), agentQualityScore
  (denormalised tier from Agent.qualityScore), similarCount, and gate inquiryCount
  (null for public callers; visible to listing owner or ADMIN)
- listing-read.queries: select agent.qualityScore, derive tier, count similar listings
  in the same query via prisma.listing.count
- GetListingQuery: add optional CallerContext (userId, role) for access control
- GetListingHandler: inject AVM_SERVICE, fire AVM estimation with 24 h valuation cache,
  gracefully degrade to null on AVM failure, redact inquiryCount for non-privileged callers
- OptionalJwtAuthGuard: new guard that sets request.user without throwing for anonymous
  requests; used on GET :id so the controller can pass caller identity to the query
- ListingsModule: import AnalyticsModule so AVM_SERVICE is available for injection
- CacheTTL: add VALUATION_LISTING (86400 s / 24 h)
- Tests: 14 unit tests + 3 snapshot tests (public / owner / admin roles), all passing

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/analytics/index.ts

@@ -1,3 +1,5 @@
 export { AnalyticsModule } from './analytics.module';
 export { MARKET_INDEX_REPOSITORY, IMarketIndexRepository } from './domain/repositories/market-index.repository';
 export { VALUATION_REPOSITORY, IValuationRepository } from './domain/repositories/valuation.repository';
+export { AVM_SERVICE } from './domain/services/avm-service';
+export type { IAVMService, AVMParams, ValuationResult } from './domain/services/avm-service';