cleanup: remove dead code and duplicate docs

- Remove session-ses_2f27.md (161KB raw session log)
- Remove 49 ROOT_* duplicate files across REFERENCE/
- Remove 14 duplicate files between REFERENCE/ root and history/
- Remove asr_legacy.rs (dead code, replaced by asr.rs)
- Remove src/core/worker/ (duplicate JobWorker)
- Remove src/core/layers/ (empty directory)
- Remove 4 .bak files in src/
- Remove 7 dead private methods in worker/processor.rs
- Remove backup directory from git tracking

scripts/utils/pose_transition_analyzer.py

@@ -13,13 +13,11 @@ Output:
 3. Stability score per trace
 """
 
-import sys
 import json
 import argparse
 import numpy as np
 import matplotlib.pyplot as plt
-from typing import Dict, List
-from collections import defaultdict
+from typing import Dict
 
 
 def analyze_pose_transitions(face_data: Dict) -> Dict:
@@ -199,7 +197,7 @@ def print_transition_analysis(analysis: Dict) -> None:
         print(f"Stability Score: {data['stability_score']} (0-1, higher = more stable)")
         print(f"Longest Stable Pose: {data['longest_stable_pose']['angle']} ({data['longest_stable_pose']['duration_frames']} frames)")
         
-        print(f"\nPose Average Duration:")
+        print("\nPose Average Duration:")
         for angle, avg_dur in data['pose_avg_duration'].items():
             print(f"  {angle}: {avg_dur} frames")