Add CooldownConfig

To facilitate using dependency cooldowns, this commit adds a class
CooldownConfig to represent a user’s desired cooldown settings: a list
of ages (specified as finite durations, using the same string syntax as
supported for pullRequests.frequency), each with a list of
UpdatePatterns for the age to apply to.

Author: emdash-ie

modules/core/src/main/scala/org/scalasteward/core/repoconfig/CooldownConfig.scala

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2018-2025 Scala Steward contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.scalasteward.core.repoconfig
+
+import io.circe.{Codec, Decoder, Encoder}
+import io.circe.generic.semiauto.deriveCodec
+import scala.concurrent.duration.FiniteDuration
+import cats.syntax.either.*
+
+import org.scalasteward.core.util.dateTime.parseFiniteDuration
+
+final case class CooldownConfig(
+    age: FiniteDuration,
+    artifacts: List[UpdatePattern] = List.empty
+)
+
+object CooldownConfig {
+  implicit val codec: Codec[CooldownConfig] = deriveCodec
+  implicit val finiteDurationDecoder: Decoder[FiniteDuration] =
+    Decoder[String].emap(s => parseFiniteDuration(s).leftMap(_.toString))
+  implicit val finiteDurationEncoder: Encoder[FiniteDuration] =
+    Encoder[String].contramap(_.toString)
+}

modules/core/src/main/scala/org/scalasteward/core/repoconfig/UpdatesConfig.scala

@@ -40,7 +40,8 @@ final case class UpdatesConfig(
     private val ignore: Option[List[UpdatePattern]] = None,
     private val retracted: Option[List[RetractedArtifact]] = None,
     limit: Option[NonNegInt] = UpdatesConfig.defaultLimit,
-    private val fileExtensions: Option[List[String]] = None
+    private val fileExtensions: Option[List[String]] = None,
+    private val cooldown: Option[List[CooldownConfig]] = None
 ) {
   private[repoconfig] def pinOrDefault: List[UpdatePattern] =
     pin.getOrElse(Nil)