Restructure SAM rough mask workflow for sidebar preview

- Add roughMaskThumbnailScale state with $watch to sync with main scale slider
- Update sidebar thumbnail to use transform:scale() for consistent zoom between views
- Modify openRoughMaskInNewWindow() to create HTML page with matching scale
- Add denoise strength slider (10-100%) visible only when rough mask exists
- Backend already supports denoise_strength parameter in prepare_mask_workflow_with_start()
- Rough mask auto-clears after successful extraction
- Add Playwright tests for UI changes and API parameter acceptance

tools/ora_editor/services/comfyui.py

@@ -279,6 +279,7 @@ class ComfyUIService:
         polygon_points: list | None = None,
         polygon_color: str = '#FF0000',
         polygon_width: int = 2,
+        denoise_strength: float = 0.8,
         workflow_template: dict | None = None
     ) -> dict:
         """Prepare the mask extraction workflow with a starting mask (lower denoise)."""
@@ -319,6 +320,9 @@ class ComfyUIService:
         if "50" in workflow and 'inputs' in workflow["50"]:
             workflow["50"]["inputs"]["seed"] = seed
         
+        if "1:65" in workflow and 'inputs' in workflow["1:65"]:
+            workflow["1:65"]["inputs"]["denoise"] = denoise_strength
+        
         if "96" in workflow and 'inputs' in workflow["96"]:
             metadata = f"{batch_id}:{mask_index}" if batch_id else str(mask_index)
             workflow["96"]["inputs"]["external_uid"] = metadata