admin: simplify template tagging flow

frontend/src/composables/useAdminCustomItems.js

@@ -89,7 +89,7 @@ export function useAdminCustomItems({
   function openCustomItemModal(item) {
     modalTargetCustomItem.value = item || null
     customItemModalDraftLabel.value = item?.label || ''
-    customItemModalDraftTags.value = Array.isArray(item?.tags) ? item.tags.join(', ') : ''
+    customItemModalDraftTags.value = Array.isArray(item?.tags) ? [...item.tags] : []
     customItemModalTargetTemplateId.value = ''
     customItemReplacementQuery.value = ''
     customItemReplacementItems.value = []
@@ -104,7 +104,7 @@ export function useAdminCustomItems({
     customItemDeleteModalOpen.value = false
     modalTargetCustomItem.value = null
     customItemModalDraftLabel.value = ''
-    customItemModalDraftTags.value = ''
+    customItemModalDraftTags.value = []
     customItemModalLabelSaving.value = false
     customItemModalTargetTemplateId.value = ''
     customItemReplacementQuery.value = ''
@@ -203,8 +203,7 @@ export function useAdminCustomItems({
     const nextLabel = customItemModalDraftLabel.value.trim().slice(0, 60)
     const nextTags = Array.from(
       new Set(
-        String(customItemModalDraftTags.value || '')
-          .split(',')
+        (Array.isArray(customItemModalDraftTags.value) ? customItemModalDraftTags.value : [])
           .map((tag) => tag.trim().replace(/^#/, '').slice(0, 40))
           .filter(Boolean)
       )
@@ -224,7 +223,7 @@ export function useAdminCustomItems({
       item.label = data.item?.label || nextLabel
       item.tags = Array.isArray(data.item?.tags) ? data.item.tags : nextTags
       customItemModalDraftLabel.value = item.label
-      customItemModalDraftTags.value = item.tags.join(', ')
+      customItemModalDraftTags.value = [...item.tags]
       customItems.value = customItems.value.map((entry) => (entry.id === item.id ? { ...entry, label: item.label, tags: item.tags } : entry))
       toast.success('아이템 메타를 변경했어요.')
     } catch (e) {