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/face_count_comparison.py

@@ -5,9 +5,7 @@ Face Detection Count Comparison
 """
 
 import json
-import sys
 from pathlib import Path
-from collections import defaultdict
 
 def load_results(filepath):
     """加载检测结果"""
@@ -172,7 +170,7 @@ def main():
     
     stats = analyze_detection_distribution(results_a, results_b, results_c)
     
-    print(f"| 版本 | 总人脸数 | 检测帧数 | 有人脸帧 | 无人脸帧 | 平均每帧 | 最多人脸 |")
+    print("| 版本 | 总人脸数 | 检测帧数 | 有人脸帧 | 无人脸帧 | 平均每帧 | 最多人脸 |")
     print("|------|---------|---------|---------|---------|---------|---------|")
     
     for name, s in stats.items():
@@ -187,14 +185,14 @@ def main():
     print(f"共有 {len(comparison)} 帧检测数量不同")
     print()
     
-    print(f"| 帧号 | 时间(秒) | InsightFace | MediaPipe | OpenCV | 最大差异 |")
+    print("| 帧号 | 时间(秒) | InsightFace | MediaPipe | OpenCV | 最大差异 |")
     print("|------|---------|------------|----------|--------|---------|")
     
     for item in comparison[:30]:  # 只显示前30帧
         print(f"| {item['frame']} | {item['timestamp']:.2f} | {item['insightface']} | {item['mediapipe']} | {item['opencv']} | {item['diff']} |")
     
     if len(comparison) > 30:
-        print(f"| ... | ... | ... | ... | ... | ... |")
+        print("| ... | ... | ... | ... | ... | ... |")
         print(f"| 共 {len(comparison)} 帧有差异 |")
     
     print()
@@ -212,7 +210,7 @@ def main():
     
     if mediapipe_missed:
         print("MediaPipe漏检详情（前10帧）:")
-        print(f"| 帧号 | InsightFace检测 | OpenCV检测 |")
+        print("| 帧号 | InsightFace检测 | OpenCV检测 |")
         print("|------|----------------|-----------|")
         for m in mediapipe_missed[:10]:
             print(f"| {m['frame']} | {m.get('insightface_count', m.get('others_count', '?'))} | {m.get('opencv_count', '?')} |")
@@ -225,7 +223,7 @@ def main():
     
     print(f"以InsightFace为基准（{baseline}张人脸）:")
     print()
-    print(f"| 版本 | 检测数 | 检测率 | 漏检数 |")
+    print("| 版本 | 检测数 | 检测率 | 漏检数 |")
     print("|------|--------|--------|--------|")
     
     for name, s in stats.items():