ai: Prefer GATTR [ci skip]

Author: krlmlr

AGENTS.md

@@ -100,6 +100,7 @@ If exporting a new function from the C library:
 - Ensure it is autogenerated
 - Add tests for the `_impl` function
 - Name all arguments in all calls to the `_impl` function
+- For graph constructors, prefer `GATTR` and `GATTR-PARAM` in Stimulus over manually assigning attributes
 
 ## File Structure and Organization