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/jobs/worker.go

@@ -13,6 +13,7 @@ import (
 
 	"evobgp/internal/birddeploy"
 	"evobgp/internal/birdfmt"
+	"evobgp/internal/httpclient"
 	"evobgp/internal/nodedispatch"
 	"evobgp/internal/observability"
 	"evobgp/internal/pipeline"
@@ -70,7 +71,7 @@ type revisionLogEntry struct {
 	Message        string   `json:"message"`
 }
 
-var defaultWorkerHTTP = &http.Client{Timeout: 45 * time.Second}
+var defaultWorkerHTTP = httpclient.New(httpclient.DefaultTimeout)
 
 func (w *Worker) httpClient() *http.Client {
 	if w != nil && w.HTTPClient != nil {