fix handling of UnsignedByte

This tweaks the handling of UnsignedByte within the trace generator.
Previously, it was not handling signed values correctly.

Author: DavePearce

pkg/cmd/generate/class.go

@@ -456,7 +456,7 @@ func generateJavaModuleColumnSetter[F any](className string, methodName string,
 func generateJavaModuleLegacyColumnSetter(className string, methodName string, builder indentBuilder) {
 	i1Builder := builder.Indent()
 	builder.WriteIndentedString("public ", className, " ", methodName, "(final UnsignedByte val) {\n")
-	i1Builder.WriteIndentedString("return ", methodName, "(val.toByte());\n")
+	i1Builder.WriteIndentedString("return ", methodName, "(val.toByte()&0xff);\n")
 	builder.WriteIndentedString("}\n\n")
 }