docs(cvl): disambiguating same-name user-defined types by originating contract

docs/cvl/types.md

@@ -154,6 +154,20 @@ Child.ParentFileType      invalid2; // user-defined types are not inherited
 Parent.ChildFileType      invalid3; // ChildFileType is not visible in Parent
 ```
 
+```{note}
+If two user-defined types in the {term}`scene` share the same qualified name but
+have **different** definitions — for example two vendored libraries both named
+`Math`, one declaring `enum Rounding { Floor, Ceil, Trunc, Expand }` and the other
+`enum Rounding { Down, Up, Zero }` — then `Math.Rounding` is ambiguous and is
+rejected.  (Same-named types with *identical* definitions are treated as one type
+and remain usable.)  To disambiguate, qualify the type by a contract that *imports*
+the definition you want, rather than by the duplicated declaring library: if `Vault`
+imports the first `Math`, then `Vault.Rounding` names that library's `Rounding`, and you can refer to fields using `Vault.Rounding.Floor`.
+Solidity forbids importing two same-named libraries into one file except under
+aliases, so a disambiguating contract normally imports just one of them; a contract
+that (via aliases) imports both is itself ambiguous.
+```
+
 Additional CVL types
 --------------------