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/routes/mask.py

@@ -116,6 +116,7 @@ def api_mask_extract():
     comfy_url = data.get('comfy_url', COMFYUI_BASE_URL)
     count = min(max(data.get('count', 1), 1), 10)
     start_mask_path = data.get('start_mask_path', None)
+    denoise_strength = data.get('denoise_strength', 0.8)
     
     logger.info(f"[MASK EXTRACT] Subject: {subject}")
     logger.info(f"[MASK EXTRACT] Use polygon: {use_polygon}")
@@ -195,6 +196,7 @@ def api_mask_extract():
                 polygon_points=polygon_points,
                 polygon_color=polygon_color,
                 polygon_width=polygon_width,
+                denoise_strength=denoise_strength,
                 workflow_template=workflow_template
             )
         else: