Update publications from DBLP

Author: github-actions[bot]

_data/publications.yml

@@ -8,6 +8,17 @@
 # Entries are matched by `key`, falling back to the title, so hand edits
 # follow a paper when DBLP re-keys it from a preprint to a published record.
 
+- key: "conf/pkdd/SparrenbergDS26"
+  title: "Grokking Is a Geometric Phase Transition: Archetypal Analysis Reveals Causal Structure in Transformer Representations"
+  authors:
+    - "Lorenz Sparrenberg"
+    - "Tobias Deußer"
+    - "Rafet Sifa"
+  year: 2027
+  venue: "ECML PKDD"
+  type: "inproceedings"
+  url: "https://doi.org/10.1007/978-3-032-37670-1_29"
+  dblp: "https://dblp.org/db/conf/pkdd/pkdd2026-5.html#SparrenbergDS26"
 - key: "manual/thesis/deusser2026"
   title: "Hybrid Representation Learning for Information Extraction"
   authors: