✨ Enhance observability and error handling in NATS integration. Introduce comprehensive OpenTelemetry support with environment-based sampling and semantic attributes for tracing and metrics. Implement an advisory dead-letter queue (DLQ) handler for managing message delivery failures. Update NATS consumer to utilize structured logging and improve error handling strategies. Refactor configuration files for OpenTelemetry collector in both development and production environments, ensuring robust telemetry integration. Enhance documentation to reflect new features and best practices for observability.

internal/infra/nats/utils.go

@@ -78,3 +78,41 @@ func mapReplayPolicy(value string) nats.ReplayPolicy {
 		return nats.ReplayInstantPolicy
 	}
 }
+
+// shouldBootstrapStream checks if streams should be auto-created based on environment.
+func shouldBootstrapStream() bool {
+	switch strings.ToLower(os.Getenv("GO_ENV")) {
+	case "", "dev", "development", "test", "testing":
+		return true
+	default:
+		return false
+	}
+}
+
+// containsSubject checks if a subject exists in a list of subjects.
+func containsSubject(subjects []string, target string) bool {
+	for _, s := range subjects {
+		if s == target {
+			return true
+		}
+	}
+	return false
+}
+
+// dedupeSubjects removes duplicate and empty subjects from a list.
+func dedupeSubjects(subjects []string) []string {
+	seen := make(map[string]struct{})
+	result := make([]string, 0, len(subjects))
+	for _, subj := range subjects {
+		subj = strings.TrimSpace(subj)
+		if subj == "" {
+			continue
+		}
+		if _, ok := seen[subj]; ok {
+			continue
+		}
+		seen[subj] = struct{}{}
+		result = append(result, subj)
+	}
+	return result
+}