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>

models/comfyui/workflows/advanced/animatediff-video-production-v1.json

@@ -11,8 +11,8 @@
       "order": 0,
       "mode": 0,
       "properties": {"Node name for S&R": "CheckpointLoaderSimple"},
-      "widgets_values": ["sd_xl_base_1.0.safetensors"],
-      "title": "SDXL Checkpoint Loader",
+      "widgets_values": ["v1-5-pruned-emaonly.safetensors"],
+      "title": "SD 1.5 Checkpoint Loader",
       "outputs": [
         {"name": "MODEL", "type": "MODEL", "links": [1], "slot_index": 0},
         {"name": "CLIP", "type": "CLIP", "links": [2, 3], "slot_index": 1},
@@ -203,14 +203,14 @@
       ],
       "requirements": {
         "models": [
-          "stable-diffusion-xl-base-1.0",
-          "animatediff-motion-module"
+          "stable-diffusion-v1-5",
+          "animatediff-motion-module-v15"
         ],
         "custom_nodes": [
           "ComfyUI-AnimateDiff-Evolved",
           "ComfyUI-VideoHelperSuite"
         ],
-        "vram_min": "18GB"
+        "vram_min": "12GB"
       },
       "parameters": {
         "prompt": {