fix: adding fvcore in requirement.txt

requirements.txt

@@ -13,7 +13,7 @@ torchvision==0.19.1+cpu
 
 # ── HuggingFace stack ─────────────────────────────────────────────
 # transformers unpinned — let pip resolve to avoid conflicts with ultralytics
-transformers
+transformers>=4.40.0,<5.0.0
 huggingface_hub>=0.26.0
 safetensors>=0.4.0
 tokenizers>=0.20.0