fix: enable UUID field overrides with patch

chimney/src/main/scala/io/scalaland/chimney/internal/compiletime/derivation/transformer/rules/TransformProductToProductRuleModule.scala

@@ -22,6 +22,10 @@ private[compiletime] trait TransformProductToProductRuleModule { this: Derivatio
     def expand[From, To](implicit ctx: TransformationContext[From, To]): DerivationResult[Rule.ExpansionResult[To]] =
       // From is checked after To, because extraction always succeeds
       (Type[To], Type[From]) match {
+        case (l, r) if r <:< l && ctx.config.areLocalFlagsAndOverridesEmpty =>
+          DerivationResult.attemptNextRuleBecause(
+            s"Type ${Type.prettyPrint[From]} <:< ${Type.prettyPrint[To]}. Falling back to TransformSubtypesRule"
+          )
         case (HasCustomConstructor(constructorOverride), Product.Extraction(fromExtractors)) =>
           mapOverridesAndExtractorsToConstructorArguments[From, To](fromExtractors, constructorOverride)
         case (Product.Constructor(parameters, constructor), Product.Extraction(fromExtractors)) =>

chimney/src/test/scala/io/scalaland/chimney/PatcherProductSpec.scala

@@ -18,6 +18,30 @@ class PatcherProductSpec extends ChimneySpec {
     foo.using(bar).patch ==> Foo(10, "", 10.0)
   }
 
+  test(
+    """patch an product type object with a product type patch object containing a non-self-transformable pojo"""
+  ) {
+    object UUIDish {
+      def randomUUID(): UUIDish = {
+        val ng = scala.util.Random
+        new UUIDish(ng.nextLong(), ng.nextLong())
+      }
+    }
+    class UUIDish(mostSigBits: Long, leastSigBits: Long) {
+      override def toString: String = s"$mostSigBits::$leastSigBits"
+    }
+    case class Foo(id: Int, externalReference: UUIDish)
+    case class Bar(externalReference: UUIDish)
+
+    val uuid1 = UUIDish.randomUUID()
+    val uuid2 = UUIDish.randomUUID()
+    val foo = Foo(42, uuid1)
+    val bar = Bar(uuid2)
+
+    foo.using(bar).patch ==> Foo(42, uuid2)
+    foo.patchUsing(bar) ==> Foo(42, uuid2)
+  }
+
   test(
     "patch a product with non-Option field with a product type patch object with all Option fields, applying value from Some and leaving original value in None"
   ) {