Managed Agents: fix statuses query param + dedupe updateAgent metadata

- listSessions sent statuses as `statuses`; the API requires the bracketed
  array name `statuses[]` (400 otherwise). Verified live that both
  `created_at[gte/lte]` and `statuses[]` filters are now accepted.
- updateAgent now uses the shared metadataPatchJson helper instead of an
  inline copy.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: peterbanda

anthropic-client/src/main/scala/io/cequence/openaiscala/anthropic/service/impl/AnthropicServiceImpl.scala

@@ -382,10 +382,6 @@ private[service] trait AnthropicServiceImpl extends Anthropic {
     agentId: String,
     settings: AnthropicUpdateAgentSettings
   ): Future[Agent] = {
-    val metadataJson = settings.metadata.map { m =>
-      JsObject(m.map { case (k, v) => k -> v.map(JsString(_)).getOrElse(JsNull) })
-    }
-
     val bodyParams: Seq[(Param, Option[JsValue])] = Seq(
       Param.version -> Some(JsNumber(settings.version)),
       Param.name -> settings.name.map(JsString),
@@ -395,7 +391,7 @@ private[service] trait AnthropicServiceImpl extends Anthropic {
       Param.tools -> settings.tools.map(Json.toJson(_)),
       Param.mcp_servers -> settings.mcpServers.map(Json.toJson(_)),
       Param.skills -> settings.skills.map(Json.toJson(_)),
-      Param.metadata -> metadataJson,
+      Param.metadata -> settings.metadata.map(metadataPatchJson),
       Param.multiagent -> settings.multiagent.map(Json.toJson(_))
     )
 

anthropic-client/src/main/scala/io/cequence/openaiscala/anthropic/service/impl/EndPoint.scala

@@ -82,7 +82,8 @@ object Param {
   case object deployment_id extends Param
   case object memory_store_id extends Param
   case object order extends Param
-  case object statuses extends Param
+  // array query param — the API expects the bracketed name `statuses[]`
+  case object statuses extends Param("statuses[]")
   // deployments
   case object initial_events extends Param
   case object schedule extends Param