fix(openai): normalize automation heartbeat bootstrap

backend/internal/handler/openai_gateway_handler.go

@@ -1756,7 +1756,7 @@ func isCodexAutomationCandidate(item map[string]any) bool {
 		return false
 	}
 	output, ok := item["output"].(string)
-	return ok && validCodexAutomationBootstrap(output)
+	return ok && (validCodexAutomationBootstrap(output) || validCodexAutomationHeartbeat(output))
 }
 
 func stringField(item map[string]any, key string) string {
@@ -1834,6 +1834,56 @@ func validCodexAutomationLastRun(value string) bool {
 	return err == nil && runAt.UnixMilli() == epochMillis
 }
 
+func validCodexAutomationHeartbeat(value string) bool {
+	decoder := xml.NewDecoder(strings.NewReader(value))
+	var rootSeen, automationIDSeen bool
+	var automationID bytes.Buffer
+	depth := 0
+	for {
+		token, err := decoder.Token()
+		if err == io.EOF {
+			id := automationID.String()
+			return rootSeen && automationIDSeen && depth == 0 &&
+				strings.TrimSpace(id) == id && validCodexAutomationID(id)
+		}
+		if err != nil {
+			return false
+		}
+		switch current := token.(type) {
+		case xml.StartElement:
+			depth++
+			if current.Name.Space != "" || len(current.Attr) != 0 || depth > 2 {
+				return false
+			}
+			if depth == 1 {
+				if rootSeen || current.Name.Local != "heartbeat" {
+					return false
+				}
+				rootSeen = true
+			} else if automationIDSeen || current.Name.Local != "automation_id" {
+				return false
+			}
+			automationIDSeen = depth == 2
+		case xml.EndElement:
+			if current.Name.Space != "" {
+				return false
+			}
+			depth--
+			if depth < 0 {
+				return false
+			}
+		case xml.CharData:
+			if depth == 2 {
+				_, _ = automationID.Write(current)
+			} else if len(bytes.TrimSpace(current)) != 0 {
+				return false
+			}
+		case xml.Comment, xml.ProcInst, xml.Directive:
+			return false
+		}
+	}
+}
+
 func validCodexDelegationEnvelope(value string) bool {
 	decoder := xml.NewDecoder(strings.NewReader(value))
 	var rootSeen, sourceSeen, inputSeen bool