Add built-in Cloud video template fallback

src/routes/money_printer.rs

@@ -723,6 +723,25 @@ fn workflow_prompt_from_graph(graph: &Value) -> Value {
         .unwrap_or_else(|| graph.clone())
 }
 
+fn default_cloud_seedance_prompt() -> Value {
+    json!({
+        "1": {
+            "class_type": "ByteDanceTextToVideoNode",
+            "inputs": {
+                "model": "seedance-1-0-lite-t2v-250428",
+                "prompt": "A clean vertical product demo video, minimal futuristic interface, smooth camera movement, bright studio lighting",
+                "resolution": "480p",
+                "aspect_ratio": "9:16",
+                "duration": 5,
+                "seed": 0,
+                "camera_fixed": false,
+                "watermark": false,
+                "generate_audio": false
+            }
+        }
+    })
+}
+
 async fn workflow_prompt_from_body(
     state: &AppState,
     auth: &MoneyPrinterAuth,
@@ -747,8 +766,11 @@ async fn workflow_prompt_from_body(
         .await?;
         return Ok(workflow_prompt_from_graph(&workflow.graph));
     }
+    if state.config.comfyui.uses_cloud_backend() {
+        return Ok(default_cloud_seedance_prompt());
+    }
     Err(AppError::BadRequest(
-        "Comfy API 模式需要选择真实 Comfy/Cloud 视频工作流模板，不能使用 BoosAPI 自定义节点".into(),
+        "Comfy API 模式需要选择真实 Comfy/Cloud 视频工作流模板；Cloud 模式可使用内置 Seedance 兜底模板".into(),
     ))
 }
 
@@ -856,11 +878,45 @@ fn inject_comfy_video_inputs(prompt: &mut Value, mapping: &Value, body: &Value,
 }
 
 fn repair_money_printer_comfy_prompt(prompt: &mut Value) {
+    repair_bytedance_video_nodes(prompt);
     repair_resize_image_mask_nodes(prompt);
     repair_text_generate_ltx2_prompt_nodes(prompt);
     repair_wan2_api_nodes(prompt);
 }
 
+fn repair_bytedance_video_nodes(prompt: &mut Value) {
+    let Some(nodes) = prompt.as_object_mut() else {
+        return;
+    };
+    for (_node_id, node) in nodes.iter_mut() {
+        let class_type = node.get("class_type").and_then(Value::as_str).unwrap_or_default();
+        if !matches!(class_type, "ByteDanceTextToVideoNode" | "ByteDance2TextToVideoNode") {
+            continue;
+        }
+        let Some(inputs) = node.get_mut("inputs").and_then(Value::as_object_mut) else {
+            continue;
+        };
+        if let Some(duration) = inputs.get("duration").and_then(value_to_duration_seconds) {
+            inputs.insert("duration".to_string(), json!(duration.clamp(3, 12)));
+        }
+        if let Some(duration) = inputs.get("model.duration").and_then(value_to_duration_seconds) {
+            inputs.insert("model.duration".to_string(), json!(duration.clamp(4, 15)));
+        }
+        if inputs
+            .get("resolution")
+            .is_some_and(|value| !matches!(value.as_str(), Some("480p" | "720p" | "1080p")))
+        {
+            inputs.insert("resolution".to_string(), json!("480p"));
+        }
+        if inputs
+            .get("aspect_ratio")
+            .is_some_and(|value| !matches!(value.as_str(), Some("16:9" | "4:3" | "1:1" | "3:4" | "9:16" | "21:9")))
+        {
+            inputs.insert("aspect_ratio".to_string(), json!("9:16"));
+        }
+    }
+}
+
 fn repair_resize_image_mask_nodes(prompt: &mut Value) {
     let Some(nodes) = prompt.as_object_mut() else {
         return;