add weights directory and allow weight files in HF repo

.gitignore

@@ -40,14 +40,8 @@ env/
 *.key
 *.secret
 
-# Model weights and downloaded third-party assets
-weights/
-*.ckpt
-*.pth
-*.pt
-*.safetensors
-*.bin
-*.msgpack
+# Model weights are stored via Xet/LFS on HF and should not be ignored here.
+# *.ckpt *.pth *.pt *.safetensors *.bin *.msgpack are tracked by .gitattributes.
 
 # Datasets and large local data
 data/