Fix requirements: Add faiss-cpu

requirements.txt

@@ -44,7 +44,7 @@ timm
 
 # --- FAISS (install separately for GPU - see README) ---
 # faiss-gpu  -> pip install faiss-gpu  (CUDA)
-# faiss-cpu  -> pip install faiss-cpu  (CPU only)
+faiss-cpu
 
 # --- Object Detection & Tracking ---
 # ByteTrack / DeepSORT dependencies