feat(analytics): add GET /analytics/market-snapshot endpoint

Dashboard tile endpoint returning activeCount, avgPrice, medianPrice,
priceChangePct (1d/7d/30d), avgPricePerM2, daysOnMarket, newListings24h.
Redis cache-aside with 5min TTL. CQRS query handler with parallel
Prisma queries for p95 <200ms on cache hit.

Refs: TEC-3049

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

apps/api/src/modules/shared/infrastructure/cache.service.ts

@@ -32,6 +32,8 @@ export const CacheTTL = {
   PLAN_LIST: 3600, // 1 hour
   /** Reference data (districts, wards) — very long TTL, static data */
   REFERENCE_DATA: 86400, // 24 hours
+  /** Market snapshot — 5 min TTL, dashboard tile data */
+  MARKET_SNAPSHOT: 300, // 5 min
 } as const;
 
 export enum CachePrefix {
@@ -48,6 +50,7 @@ export enum CachePrefix {
   PLAN_LIST = 'cache:plan:list',
   REFERENCE = 'cache:reference',
   AGENT_LISTINGS = 'cache:agent:listings',
+  MARKET_SNAPSHOT = 'cache:analytics:market_snapshot',
 }
 
 @Injectable()