little refactoring done

python_app/models/run_config_schema.py

@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass, field
+import json
 from pathlib import Path
 from typing import Any
 
@@ -131,9 +132,10 @@ class RunConfigModel:
     @classmethod
     def load_from_path(cls, path: Path) -> RunConfigModel:
         """Load JSON file from disk and decode into model."""
-        from python_app.models.run_config_codec import load_run_config
-
-        return load_run_config(path)
+        payload = json.loads(path.read_text(encoding="utf-8"))
+        if not isinstance(payload, dict):
+            raise ValueError(f"Config root must be JSON object: {path}")
+        return cls.from_dict(payload)
 
     def clone(self) -> RunConfigModel:
         """Create deep copy through codec round-trip."""