refactor(translate.go): optimize trimDividers function for clarity and efficiency

- Move the condition to check the length of lines before cloning to avoid unnecessary operation.
- Change return value to use strings.TrimSpace for consistency and to ensure the returned text does not have leading or trailing whitespace when no lines exist.

Author: bounoable

translate.go

@@ -125,12 +125,13 @@ func (t *Translator) translateChunk(ctx context.Context, chunk string, params Tr
 
 func trimDividers(text string) string {
 	lines := strings.Split(text, "\n")
-	out := slices.Clone(lines)
 
-	if len(out) < 1 {
-		return text
+	if len(lines) < 1 {
+		return strings.TrimSpace(text)
 	}
 
+	out := slices.Clone(lines)
+
 	if out[0] == "---<DOC_BEGIN>---" {
 		out = out[1:]
 	}