feat: add SD 1.5 model and update AnimateDiff workflow

Changes:
- Added Stable Diffusion v1.5 model to comfyui_models.yaml
  - Required for AnimateDiff motion modules (mm_sd_v15_v2.ckpt)
  - Size: 4GB, VRAM: 8GB
- Updated AnimateDiff workflow to use SD 1.5 instead of SDXL
  - Changed checkpoint from sd_xl_base_1.0.safetensors to v1-5-pruned-emaonly.safetensors
  - Updated VRAM requirement from 18GB to 12GB
  - Updated model requirements in metadata

AnimateDiff v15 motion modules are not compatible with SDXL.
This resolves: "Motion module 'mm_sd_v15_v2.ckpt' is intended for SD1.5 models"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

comfyui_models.yaml

@@ -53,6 +53,19 @@ model_categories:
         - source: "flux1-dev.safetensors"
           dest: "flux1-dev.safetensors"
 
+    - repo_id: runwayml/stable-diffusion-v1-5
+      description: SD 1.5 - For AnimateDiff
+      size_gb: 4
+      essential: true
+      category: image
+      type: checkpoints
+      format: fp16
+      vram_gb: 8
+      notes: Stable Diffusion 1.5 required for AnimateDiff motion modules
+      files:
+        - source: "v1-5-pruned-emaonly.safetensors"
+          dest: "v1-5-pruned-emaonly.safetensors"
+
     - repo_id: stabilityai/stable-diffusion-xl-base-1.0
       description: SDXL Base 1.0 - Industry standard
       size_gb: 7