템플릿 slug 구조와 빈 DB 초기화를 정리

backend/src/routes/tierlists.js

@@ -12,6 +12,7 @@ const {
   createCustomItem,
   createTemplateRequest,
   findUserById,
+  findTopicByIdentifier,
   favoriteTierList,
   unfavoriteTierList,
   duplicateTierListForUser,
@@ -234,14 +235,15 @@ router.post('/template-request', requireAuth, async (req, res) => {
   if (!parsed.success) return res.status(400).json({ error: 'bad_request' })
 
   const payload = parsed.data
-  const topicId = payload.topicId
+  const topic = await findTopicByIdentifier(payload.topicId)
+  if (!topic) return res.status(404).json({ error: 'not_found' })
   const normalizedBoardItems = payload.boardItems.map(normalizePoolItem)
   const customItems = normalizedBoardItems.filter((item) => item?.origin === 'custom')
   if (!customItems.length) return res.status(400).json({ error: 'custom_items_required' })
 
   if (payload.type === 'create') {
-    if (topicId !== FREEFORM_TOPIC_ID) return res.status(400).json({ error: 'freeform_required' })
-  } else if (topicId === FREEFORM_TOPIC_ID) {
+    if (topic.id !== FREEFORM_TOPIC_ID) return res.status(400).json({ error: 'freeform_required' })
+  } else if (topic.id === FREEFORM_TOPIC_ID) {
     return res.status(400).json({ error: 'topic_template_required' })
   }
 
@@ -260,8 +262,8 @@ router.post('/template-request', requireAuth, async (req, res) => {
       type: payload.type,
       requesterId: req.session.userId,
       sourceTierListId: sourceTierList?.id || '',
-      sourceTopicId: topicId,
-      targetTopicId: payload.type === 'update' ? topicId : '',
+      sourceTopicId: topic.id,
+      targetTopicId: payload.type === 'update' ? topic.id : '',
       title: payload.requestTitle,
       description: payload.requestDescription,
       thumbnailSrc: payload.thumbnailSrc || '',
@@ -283,7 +285,8 @@ router.post('/', requireAuth, async (req, res) => {
   const parsed = tierListUpsertSchema.safeParse(req.body)
   if (!parsed.success) return res.status(400).json({ error: 'bad_request' })
   const payload = parsed.data
-  const topicId = payload.topicId
+  const topic = await findTopicByIdentifier(payload.topicId)
+  if (!topic) return res.status(404).json({ error: 'not_found' })
   const normalizedPool = payload.pool.map(normalizePoolItem)
 
   let existing = null
@@ -313,7 +316,7 @@ router.post('/', requireAuth, async (req, res) => {
   const created = await saveTierList({
     id: nanoid(),
     authorId: req.session.userId,
-    topicId,
+    topicId: topic.id,
     title: payload.title,
     thumbnailSrc: payload.thumbnailSrc || '',
     description: payload.description || '',