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/test_florence2_stamps.py

@@ -5,9 +5,7 @@ Florence-2 is superior to OWL-ViT for small objects and detailed description.
 """
 
 import os
-import json
 import cv2
-import torch
 from PIL import Image
 from transformers import AutoProcessor, AutoModelForCausalLM
 
@@ -32,7 +30,7 @@ if not ret:
 # Save raw frame
 raw_path = os.path.join(OUTPUT_DIR, f"raw_{int(TIMESTAMP)}.jpg")
 cv2.imwrite(raw_path, frame)
-print(f"💾 Raw frame saved.")
+print("💾 Raw frame saved.")
 
 image_pil = Image.fromarray(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB))