Add ComfyUI node integration and fix compatibility issues

- Add ComfyUI custom nodes: model loader, t2v, i2v, v2v
- Fix kernels import: move to try block for graceful fallback when not installed
- Fix diffusers compatibility: add fallback imports for HeliosLoraLoaderMixin,
  HeliosTransformer3DModel, HeliosScheduler, and apply_lora_scale
- Fix infer_helios: cast num_blocks_per_group to int, add low_cpu_mem_usage
- Add rh_config.json, model index compat, and deployment scripts

Made-with: Cursor

helios/diffusers_version/transformer_helios_diffusers.py

@@ -30,7 +30,14 @@ from diffusers.models.embeddings import PixArtAlphaTextProjection, TimestepEmbed
 from diffusers.models.modeling_outputs import Transformer2DModelOutput
 from diffusers.models.modeling_utils import ModelMixin
 from diffusers.models.normalization import FP32LayerNorm
-from diffusers.utils import apply_lora_scale, logging
+from diffusers.utils import logging
+try:
+    from diffusers.utils import apply_lora_scale
+except ImportError:
+    def apply_lora_scale(key):
+        def decorator(fn):
+            return fn
+        return decorator
 from diffusers.utils.torch_utils import maybe_allow_in_graph