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>

install.py

@@ -0,0 +1,47 @@
+import subprocess
+import sys
+import os
+
+
+def get_cupy_package():
+    """Detect PyTorch's CUDA version and return the matching cupy package name."""
+    try:
+        import torch
+        if not torch.cuda.is_available():
+            print("[BIM-VFI] WARNING: CUDA not available. cupy requires CUDA.")
+            return None
+        cuda_version = torch.version.cuda
+        if cuda_version is None:
+            print("[BIM-VFI] WARNING: PyTorch has no CUDA version info.")
+            return None
+        major = cuda_version.split(".")[0]
+        major = int(major)
+        cupy_pkg = f"cupy-cuda{major}x"
+        print(f"[BIM-VFI] Detected CUDA {cuda_version}, will use {cupy_pkg}")
+        return cupy_pkg
+    except Exception as e:
+        print(f"[BIM-VFI] WARNING: Could not detect CUDA version: {e}")
+        return None
+
+
+def install():
+    requirements_path = os.path.join(os.path.dirname(__file__), "requirements.txt")
+    subprocess.check_call([
+        sys.executable, "-m", "pip", "install", "-r", requirements_path
+    ])
+
+    # Install cupy matching the current CUDA version
+    try:
+        import cupy
+        print("[BIM-VFI] cupy already installed, skipping.")
+    except ImportError:
+        cupy_pkg = get_cupy_package()
+        if cupy_pkg:
+            print(f"[BIM-VFI] Installing {cupy_pkg} to match PyTorch CUDA...")
+            subprocess.check_call([
+                sys.executable, "-m", "pip", "install", cupy_pkg
+            ])
+
+
+if __name__ == "__main__":
+    install()