feat(jobs): add durable PG queue reclaim, slog, and richer metrics

JSON slog в ключевых пакетах; Prometheus path_group, job_audit_depth, upstream breaker; job_audit ClaimQueued/ReclaimStaleRunning + Adopt loop для HA после рестарта.

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

internal/httpclient/circuit.go

@@ -49,6 +49,24 @@ func (b *hostBreaker) recordFailure() {
 	}
 }
 
+// SnapshotBreakers returns whether each known host breaker is currently open.
+func SnapshotBreakers() map[string]bool {
+	out := map[string]bool{}
+	hostBreakers.Range(func(key, value any) bool {
+		host, _ := key.(string)
+		b, _ := value.(*hostBreaker)
+		if b == nil {
+			return true
+		}
+		b.mu.Lock()
+		open := time.Now().Before(b.openUntil)
+		b.mu.Unlock()
+		out[host] = open
+		return true
+	})
+	return out
+}
+
 // ResetHostBreakers clears all circuit breakers (tests only).
 func ResetHostBreakers() {
 	hostBreakers = sync.Map{}