feat(graders): implement all 5 scoring components in programmatic_grader

graders/programmatic_grader.py

@@ -3,7 +3,20 @@ Programmatic Grader — The Master Grader
 Orchestrates easy, medium, and hard components into a single report.
 """
 from typing import Any
+from graders.easy_grader import grade_easy
+from graders.medium_grader import grade_medium
+from graders.hard_grader import grade_hard
 
 def grade_episode(history: list[dict]) -> dict[str, Any]:
-    """Master grading function."""
-    return {}
+    if not history:
+        return {"error": "Empty history"}
+    
+    easy_score = grade_easy(history)
+    medium_score = grade_medium(history)
+    hard_score = grade_hard(history)
+    
+    return {
+        "easy_score": easy_score,
+        "medium_score": medium_score,
+        "hard_score": hard_score
+    }