feat(sync): full code sync from release

backend/internal/service/openai_previous_response_id.go

@@ -0,0 +1,37 @@
+package service
+
+import (
+	"regexp"
+	"strings"
+)
+
+const (
+	OpenAIPreviousResponseIDKindEmpty      = "empty"
+	OpenAIPreviousResponseIDKindResponseID = "response_id"
+	OpenAIPreviousResponseIDKindMessageID  = "message_id"
+	OpenAIPreviousResponseIDKindUnknown    = "unknown"
+)
+
+var (
+	openAIResponseIDPattern = regexp.MustCompile(`^resp_[A-Za-z0-9_-]{1,256}$`)
+	openAIMessageIDPattern  = regexp.MustCompile(`^(msg|message|item|chatcmpl)_[A-Za-z0-9_-]{1,256}$`)
+)
+
+// ClassifyOpenAIPreviousResponseIDKind classifies previous_response_id to improve diagnostics.
+func ClassifyOpenAIPreviousResponseIDKind(id string) string {
+	trimmed := strings.TrimSpace(id)
+	if trimmed == "" {
+		return OpenAIPreviousResponseIDKindEmpty
+	}
+	if openAIResponseIDPattern.MatchString(trimmed) {
+		return OpenAIPreviousResponseIDKindResponseID
+	}
+	if openAIMessageIDPattern.MatchString(strings.ToLower(trimmed)) {
+		return OpenAIPreviousResponseIDKindMessageID
+	}
+	return OpenAIPreviousResponseIDKindUnknown
+}
+
+func IsOpenAIPreviousResponseIDLikelyMessageID(id string) bool {
+	return ClassifyOpenAIPreviousResponseIDKind(id) == OpenAIPreviousResponseIDKindMessageID
+}