fix: keep a workspace model's base model when cloning it from the admin Models settings and hide Clone for arena models (#30080)

src/lib/components/admin/Settings/Models.svelte

@@ -638,7 +638,7 @@
 		model = await getFullModel(model);
 		sessionStorage.model = JSON.stringify({
 			...model,
-			base_model_id: model.id,
+			...(isPresetModel(model) ? {} : { base_model_id: model.id }),
 			id: `${model.id}-clone`,
 			name: `${model.name} (Clone)`
 		});

src/lib/components/admin/Settings/Models/ModelMenu.svelte

@@ -197,7 +197,7 @@
 				<div class="flex items-center">{$i18n.t('Copy Link')}</div>
 			</button>
 
-			{#if model?.is_active ?? true}
+			{#if (model?.is_active ?? true) && model?.owned_by !== 'arena'}
 				<button
 					class="select-none flex w-full gap-2 items-center h-[1.6875rem] px-2 text-[0.8125rem] font-normal cursor-pointer hover:bg-gray-50/40 dark:hover:bg-gray-800/40 rounded-xl"
 					on:click={() => runAndClose(cloneHandler)}