wire up existing http.Client for sibling requests

cmd/relay/forward.go

···
 	"io"
 	"net/http"
 	"strings"
-	"time"
 
 	"github.com/bluesky-social/indigo/cmd/relay/relay"
 
···
 			s.logger.Info("not re-forwarding request to sibling relay", "header", "User-Agent", "value", ua)
 			return
 		}
-	}
-
-	// TODO: could turn this in to a shared/persistent client
-	client := http.Client{
-		Timeout: 10 * time.Second,
 	}
 
 	for _, rawHost := range s.config.SiblingRelayHosts {
···
 		// add Via header (critical to prevent forwarding loops)
 		upstreamReq.Header.Add("Via", req.Proto+" atproto-relay")
 
-		upstreamResp, err := client.Do(upstreamReq)
+		upstreamResp, err := s.siblingClient.Do(upstreamReq)
 		if err != nil {
 			s.logger.Warn("forwarded admin HTTP request failed", "method", req.Method, "sibling", hostname, "url", u.String(), "err", err)
 			continue

cmd/relay/service.go

···
 	relay  *relay.Relay
 	config ServiceConfig
 
-	crawlForwardClient http.Client
+	siblingClient http.Client
 }
 
 type ServiceConfig struct {
···
 	}
 
 	svc := &Service{
-		logger:             slog.Default().With("system", "relay"),
-		relay:              r,
-		config:             *config,
-		crawlForwardClient: http.Client{},
+		logger: slog.Default().With("system", "relay"),
+		relay:  r,
+		config: *config,
+		siblingClient: http.Client{
+			Timeout: 10 * time.Second,
+		},
 	}
-	svc.crawlForwardClient.Timeout = time.Second * 5
 
 	return svc, nil
 }