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/asrx_self/main.py

@@ -16,7 +16,6 @@ Self-implemented ASRX - 自實作說話人分離系統
 import sys
 import json
 import time
-import numpy as np
 from pathlib import Path
 
 # 導入自定義模組
@@ -182,7 +181,7 @@ class SelfASRX:
         result["processing_time"] = round(total_time, 2)
         result["realtime_factor"] = round(result["total_duration"] / total_time, 2)
 
-        print(f"\n[SelfASRX] Processing completed!")
+        print("\n[SelfASRX] Processing completed!")
         print(f"  Total time: {total_time:.2f}s")
         print(f"  Realtime factor: {result['realtime_factor']:.2f}x")
         print(f"  Detected speakers: {estimated_n_speakers}")
@@ -249,14 +248,14 @@ def main():
 
     # 顯示結果摘要
     if "error" not in result:
-        print(f"\n[Summary]")
+        print("\n[Summary]")
         print(f"  Audio duration: {result['total_duration']:.2f}s")
         print(f"  Speech segments: {result['n_speech_segments']}")
         print(f"  Detected speakers: {result['n_speakers']}")
         print(f"  Processing time: {result['processing_time']:.2f}s")
         print(f"  Realtime factor: {result['realtime_factor']:.2f}x")
 
-        print(f"\n[Speaker Statistics]")
+        print("\n[Speaker Statistics]")
         for speaker, stats in result["speaker_stats"].items():
             pct = stats["duration"] / result["total_duration"] * 100
             print(