Restore main README updates (arxiv link + full citation)

My initial PR commit was built on a stale local copy of README.md and overwrote two updates that had landed on main since I cached it:
- Model Report link changed from the GCS PDF to arxiv.org/pdf/2605.13986
- Citation block replaced placeholder TabPFN3 entry with the full grinsztajn2026tabpfn3technicalreport @misc entry (full author list, eprint).
This commit rebuilds README.md from current main and re-applies the two OOD-checkpoint rows. The two .ckpt files in this PR are unchanged.

README.md

@@ -26,7 +26,7 @@ tags:
 ### Model Overview
 TabPFN-3 is a transformer-based foundation model that uses in-context-learning to solve tabular prediction problems in a forward pass. 
 Inference code can be found at [https://github.com/PriorLabs/TabPFN](https://github.com/PriorLabs/TabPFN).
-More details can be found in the [Model Report](https://storage.googleapis.com/prior-labs-tabpfn-public/reports/TabPFN_3_model_report.pdf).
+More details can be found in the [Model Report](https://arxiv.org/pdf/2605.13986).
 
 ### Getting started
 First, install the inference package:
@@ -117,10 +117,12 @@ v1.0: initial release.
 
 ### Citation
 ```
-@misc{TabPFN3,
-      title={TabPFN-3},
-      author={Prior Labs},
+@misc{grinsztajn2026tabpfn3technicalreport,
+      title={TabPFN-3: Technical Report}, 
+      author={Léo Grinsztajn and Klemens Flöge and Oscar Key and Felix Birkel and Philipp Jund and Brendan Roof and Mihir Manium and Shi Bin and Hoo and Magnus Bühler and Anurag Garg and Dominik Safaric and Jake Robertson and Benjamin Jäger and Simone Alessi and Adrian Hayler and Vladyslav Moroshan and Lennart Purucker and Philipp Singer and Alan Arazi and Julien Siems and Jan Hendrik Metzen and Georg Grab and Nick Erickson and Siyuan Guo and Eliott Kalfon and Simon Bing and David Salinas and Clara Cornu and Lilly Charlotte Wehrhahn and Diana Kriuchkova and Kursat Kaya and Lydia Sidhoum and Marie Salmon and Jerry Chen and Madelon Hulsebos and Yann LeCun and Samuel Müller and Bernhard Schölkopf and Sauraj Gambhir and Noah Hollmann and Frank Hutter},
       year={2026},
-      note={Coming soon}
+      eprint={2605.13986},
+      archivePrefix={arXiv},
+      url={https://arxiv.org/abs/2605.13986}, 
 }
 ```