fix(httpclient): replace DefaultClient with timed clients and retry

Пакет httpclient: timeout 45s, idle pool, DoWithRetry. Scheduler и nodecli
используют retry; pipeline/asnresolve/jobs — httpclient.New вместо DefaultClient.

Co-authored-by: Cursor <[email protected]>

internal/asnresolve/ripestat.go

@@ -13,6 +13,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"evobgp/internal/httpclient"
 )
 
 // DefaultRIPEStatURL is the RIPEstat announced-prefixes data call (no API key).
@@ -24,7 +26,7 @@ const DefaultASOverviewURL = "https://stat.ripe.net/data/as-overview/data.json"
 // AnnouncedPrefixes returns currently announced IPv4/IPv6 prefixes for the ASN (best-effort via RIPEstat).
 func AnnouncedPrefixes(ctx context.Context, hc *http.Client, asn int64) ([]netip.Prefix, error) {
 	if hc == nil {
-		hc = http.DefaultClient
+		hc = httpclient.New(httpclient.DefaultTimeout)
 	}
 	base := strings.TrimSpace(os.Getenv("EVOBGP_RIPESTAT_ANNOUNCED_PREFIXES_URL"))
 	if base == "" {
@@ -86,7 +88,7 @@ func AnnouncedPrefixes(ctx context.Context, hc *http.Client, asn int64) ([]netip
 // ASHolderName returns the holder / organization label for the ASN from RIPEstat as-overview (best-effort).
 func ASHolderName(ctx context.Context, hc *http.Client, asn int64) (string, error) {
 	if hc == nil {
-		hc = http.DefaultClient
+		hc = httpclient.New(httpclient.DefaultTimeout)
 	}
 	base := strings.TrimSpace(os.Getenv("EVOBGP_RIPESTAT_AS_OVERVIEW_URL"))
 	if base == "" {