feat: 接入 Seedance 视频节点并增强图像节点功能

- 新增 Seedance 文生视频、图生视频、首尾帧生视频三个节点
- 新增 seedance_client.py 客户端
- 为 NanoBananaPro、BatchNanoBananaPro、全能生图节点添加「跳过错误」开关，出错时返回占位图以继续队列
- 修复 nano-banana-2-限时特价 动态端点路由（按分辨率选择）
- 统一分辨率选项命名：512 → 512px

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
+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
 
 # 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。"
@@ -79,6 +79,9 @@ NODE_CLASS_MAPPINGS = {
     "AspectRatioPreset": AspectRatioPreset,
     "MultiResPreview": MultiResPreview,
     "BatchImagesO1key": BatchImagesO1key,
+    "SeedanceT2V": SeedanceT2V,
+    "SeedanceI2V": SeedanceI2V,
+    "SeedanceFlipFlop": SeedanceFlipFlop,
 }
 
 NODE_DISPLAY_NAME_MAPPINGS = {
@@ -101,6 +104,9 @@ 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",
 }
 
 WEB_DIRECTORY = "./web"