Initial commit: ComfyUI BIM-VFI node for video frame interpolation

Wraps BiM-VFI (CVPR 2025) as a ComfyUI custom node for long video
frame interpolation with memory-safe sequential processing.

- LoadBIMVFIModel: checkpoint loader with auto-download from Google Drive
- BIMVFIInterpolate: 2x/4x/8x recursive interpolation with per-pair
  GPU processing, configurable VRAM management (all_on_gpu for high-VRAM
  setups), progress bar, and backwarp cache clearing
- Vendored inference-only architecture from KAIST-VICLab/BiM-VFI
- Auto-detection of CUDA version for cupy installation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

__init__.py

@@ -0,0 +1,11 @@
+from .nodes import LoadBIMVFIModel, BIMVFIInterpolate
+
+NODE_CLASS_MAPPINGS = {
+    "LoadBIMVFIModel": LoadBIMVFIModel,
+    "BIMVFIInterpolate": BIMVFIInterpolate,
+}
+
+NODE_DISPLAY_NAME_MAPPINGS = {
+    "LoadBIMVFIModel": "Load BIM-VFI Model",
+    "BIMVFIInterpolate": "BIM-VFI Interpolate",
+}