refactor(demo): simplify visualizer wiring and typing

Apply Oracle-guided cleanup to make the demo pipeline contract explicit and remove defensive runtime indirection while preserving existing visualization behavior.

opengait/demo/__main__.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import argparse
-import inspect
 import logging
 import sys
 
@@ -90,7 +89,6 @@ if __name__ == "__main__":
         )
 
         # Build kwargs based on what ScoliosisPipeline accepts
-        sig = inspect.signature(ScoliosisPipeline.__init__)
         pipeline_kwargs = {
             "source": args.source,
             "checkpoint": args.checkpoint,
@@ -108,10 +106,8 @@ if __name__ == "__main__":
             "silhouette_visualize_dir": args.silhouette_visualize_dir,
             "result_export_path": args.result_export_path,
             "result_export_format": args.result_export_format,
+            "visualize": args.visualize,
         }
-        if "visualize" in sig.parameters:
-            pipeline_kwargs["visualize"] = args.visualize
-
         pipeline = ScoliosisPipeline(**pipeline_kwargs)
         raise SystemExit(pipeline.run())
     except ValueError as err: