feat(ops-api/site-mappings): provision monitoring DB pool and readiness check

Open a separate pgx pool for the monitoring database, wire it into the
SiteDomainMappingService, and surface its health in /readyz. Point compose
at the dedicated monitoring-postgres service and align local/dev configs
with the per-instance ports. Also reformat the site_domain_mapping types
with gofmt while the files are touched.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

server/cmd/ops-api/main.go

@@ -44,9 +44,16 @@ func main() {
 	}
 	defer pool.Close()
 
+	monitoringPool, err := postgres.NewPool(ctx, cfg.MonitoringDatabase)
+	if err != nil {
+		logger.Sugar().Fatalf("ops-api init monitoring postgres: %v", err)
+	}
+	defer monitoringPool.Close()
+
 	accountsRepo := repository.NewAccountRepository(pool)
 	adminUsersRepo := repository.NewAdminUserRepository(pool)
 	auditsRepo := repository.NewAuditRepository(pool)
+	siteDomainMappingsRepo := repository.NewSiteDomainMappingRepository(monitoringPool)
 
 	ipRegionResolver, err := app.NewIPRegionResolver(cfg.IPRegion.V4XDBPath, cfg.IPRegion.V6XDBPath, logger)
 	if err != nil {
@@ -59,6 +66,7 @@ func main() {
 	authSvc := app.NewAuthService(accountsRepo, auditSvc, issuer)
 	accountSvc := app.NewAccountService(accountsRepo, auditSvc)
 	adminUserSvc := app.NewAdminUserService(adminUsersRepo, auditSvc, cfg.AdminUsers.DefaultPlanCode)
+	siteDomainMappingSvc := app.NewSiteDomainMappingService(siteDomainMappingsRepo, auditSvc)
 
 	if err := app.SeedDefaultAdmin(ctx, accountsRepo, app.DefaultAdminSeed{
 		Username:    cfg.DefaultAdmin.Username,
@@ -75,14 +83,16 @@ func main() {
 	engine := gin.New()
 
 	transport.RegisterRoutes(transport.Deps{
-		Engine:     engine,
-		Logger:     logger,
-		DB:         pool,
-		Issuer:     issuer,
-		Auth:       authSvc,
-		Accounts:   accountSvc,
-		AdminUsers: adminUserSvc,
-		Audits:     auditSvc,
+		Engine:       engine,
+		Logger:       logger,
+		DB:           pool,
+		MonitoringDB: monitoringPool,
+		Issuer:       issuer,
+		Auth:         authSvc,
+		Accounts:     accountSvc,
+		AdminUsers:   adminUserSvc,
+		Audits:       auditSvc,
+		SiteDomains:  siteDomainMappingSvc,
 	})
 
 	addr := fmt.Sprintf(":%d", cfg.Server.Port)