feat(digital-human): 后端转发 api_video_workflow 给 Pixelle

Co-Authored-By: Claude <noreply@anthropic.com>

src/routes/digital_human.rs

@@ -2076,6 +2076,9 @@ fn pixelle_request_body(state: &AppState, body: &Value) -> AppResult<(String, Va
     {
         request_body["tts_workflow"] = json!(value);
     }
+    if let Some(value) = optional_string(body, &["apiVideoWorkflow", "api_video_workflow"]) {
+        request_body["api_video_workflow"] = json!(value);
+    }
     if let Some(value) = reference_audio_url {
         request_body["ref_audio"] = json!(value);
     }