Update python/kicad_interface.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

python/kicad_interface.py

@@ -617,7 +617,9 @@ class KiCADInterface:
 
             sch_path = path if path and path != "." else None
             schematic = SchematicManager.create_schematic(project_name, path=sch_path, metadata=metadata)
-            file_path = f"{path}/{project_name}.kicad_sch"
+            base_name = project_name if project_name.endswith(".kicad_sch") else f"{project_name}.kicad_sch"
+            normalized_path = path or "."
+            file_path = os.path.join(normalized_path, base_name)
             success = SchematicManager.save_schematic(schematic, file_path)
 
             return {"success": success, "file_path": file_path}