Add cost service for per-VIN cost estimation

- Estimates cloud vs on-prem costs per active vehicle
- Queries feature_table_last_shard from ClickHouse (lightweight)
- 85% savings estimate with on-prem (hardware only)
- Deployed to cec-prd-cluster-1 (internal only)
- Text report endpoint at /cost/report

services/cost/main.go

@@ -29,6 +29,7 @@ func main() {
 	mux.HandleFunc("/cost/fleet", handlers.GetFleetCost)
 	mux.HandleFunc("/cost/summary", handlers.GetCostSummary)
 	mux.HandleFunc("/cost/comparison", handlers.GetCostComparison)
+	mux.HandleFunc("/cost/report", handlers.GetReport)
 
 	// Start health check server
 	healthServer := &health.HealthCheckServer{}