Add pipeline tag

This PR adds the missing `pipeline_tag` to the model card metadata so the artifact can be more easily discovered via the Hugging Face Hub's pipeline filters. No other content changes are made.

README.md

@@ -1,14 +1,15 @@
 ---
-license: mit
+datasets:
+- wzekai99/ORCA
 library_name: pytorch
+license: mit
+pipeline_tag: text-classification
 tags:
-  - test-time-training
-  - conformal-prediction
-  - reasoning
-  - early-stopping
-  - llm
-datasets:
-  - wzekai99/ORCA
+- test-time-training
+- conformal-prediction
+- reasoning
+- early-stopping
+- llm
 ---
 
 # ORCA TTT-Probes
@@ -66,4 +67,4 @@ MIT.
   journal={arXiv preprint arXiv:2604.01170},
   year={2026}
 }
-```
+```