refactor: 重构 Seedance 节点，三合一并修复轮询 Bug

- 将 SeedanceT2V / SeedanceI2V / SeedanceFlipFlop 合并为单一 Seedance 节点
- 通过图片输入自动判断模式：无图=文生视频，首帧=图生视频，首尾帧=首尾帧模式
- 修复轮询状态字段取值路径错误导致的无限循环问题
- 修复视频 URL / 末帧 URL 取值路径（result.data.content.video_url）
- 新增末帧图片 IMAGE 输出端，支持 return_last_frame 功能
- 删除水印、服务等级前端参数，移除 1.0/1.5 旧模型，去掉 1080p 分辨率
- 关闭 DEBUG 原始响应日志，仅保留用户可见进度日志

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

__init__.py

@@ -21,7 +21,7 @@ except Exception:
 
 import ssl
 
-from .nodes import NanoBananaPro, BatchNanoBananaPro, GoogleGemini, LoadFile, ImageStitchPro, SaveCleanImage, BatchCleanMetadata, VideoPreview, GoogleVeo, FluxImageEdit, UniversalLLMChat, KlingVideo, KlingFirstLastFrame, KlingMotionControlTest, QuanNengShengTu, BatchQuanNengShengTu, AspectRatioPreset, MultiResPreview, BatchImagesO1key, SeedanceT2V, SeedanceI2V, SeedanceFlipFlop
+from .nodes import NanoBananaPro, BatchNanoBananaPro, GoogleGemini, LoadFile, ImageStitchPro, SaveCleanImage, BatchCleanMetadata, VideoPreview, GoogleVeo, FluxImageEdit, UniversalLLMChat, KlingVideo, KlingFirstLastFrame, KlingMotionControlTest, QuanNengShengTu, BatchQuanNengShengTu, AspectRatioPreset, MultiResPreview, BatchImagesO1key, Seedance
 
 # 报错弹框友好文案（不修改原节点代码，仅在外层统一处理）
 _MSG_TIMEOUT = "API 请求超时，请稍后重试或检查网络。"
@@ -79,9 +79,7 @@ NODE_CLASS_MAPPINGS = {
     "AspectRatioPreset": AspectRatioPreset,
     "MultiResPreview": MultiResPreview,
     "BatchImagesO1key": BatchImagesO1key,
-    "SeedanceT2V": SeedanceT2V,
-    "SeedanceI2V": SeedanceI2V,
-    "SeedanceFlipFlop": SeedanceFlipFlop,
+    "Seedance": Seedance,
 }
 
 NODE_DISPLAY_NAME_MAPPINGS = {
@@ -104,9 +102,7 @@ NODE_DISPLAY_NAME_MAPPINGS = {
     "AspectRatioPreset": "图片宽高比预设",
     "MultiResPreview": "预览图像（v2）",
     "BatchImagesO1key": "加载图像（批量）",
-    "SeedanceT2V": "Seedance 文生视频",
-    "SeedanceI2V": "Seedance 图生视频",
-    "SeedanceFlipFlop": "Seedance 首尾帧生视频",
+    "Seedance": "Seedance 视频生成",
 }
 
 WEB_DIRECTORY = "./web"