feat: 관리자 수동 이미지 대체 기능 추가

backend/src/routes/admin.js

@@ -53,6 +53,7 @@ const {
   listRecentImageOptimizationJobs,
   clearImageOptimizationJobs,
   cleanupMissingUploadReferences,
+  replaceUploadSourceReferences,
 } = require('../db')
 const { requireAdmin } = require('../middleware/auth')
 const { createMemoryUpload, writeOptimizedImage, getImageOptimizationQueueState } = require('../lib/image-storage')
@@ -551,6 +552,57 @@ async function promoteLibraryItemToTemplateItem({ item, templateId }) {
   })
 }
 
+async function findLibraryItemForReplacement(itemId, sourceType = '') {
+  const normalizedId = String(itemId || '').trim()
+  const normalizedSourceType = String(sourceType || '').trim()
+  if (!normalizedId) return null
+
+  if (normalizedId.startsWith('asset:') || normalizedSourceType === 'asset') {
+    const assetId = normalizedId.startsWith('asset:') ? normalizedId.slice(6) : normalizedId
+    const asset = await findImageAssetById(assetId)
+    if (!asset) return null
+    return {
+      id: `asset:${asset.id}`,
+      sourceType: 'asset',
+      src: asset.src || '',
+      label: asset.labelOverride || buildItemLabelFromSrc(asset.src),
+    }
+  }
+
+  if (normalizedSourceType === 'template') {
+    const item = await findTopicItemById(normalizedId)
+    if (!item) return null
+    return {
+      id: item.id,
+      sourceType: 'template',
+      src: item.src || '',
+      label: item.label || buildItemLabelFromSrc(item.src),
+    }
+  }
+
+  const customItem = await findCustomItemById(normalizedId)
+  if (customItem) {
+    return {
+      id: customItem.id,
+      sourceType: 'user',
+      src: customItem.src || '',
+      label: customItem.label || buildItemLabelFromSrc(customItem.src),
+    }
+  }
+
+  const templateItem = await findTopicItemById(normalizedId)
+  if (templateItem) {
+    return {
+      id: templateItem.id,
+      sourceType: 'template',
+      src: templateItem.src || '',
+      label: templateItem.label || buildItemLabelFromSrc(templateItem.src),
+    }
+  }
+
+  return null
+}
+
 async function copyUploadIntoTopicAsset(src) {
   if (typeof src !== 'string') return ''
   const raw = src.trim()
@@ -760,6 +812,37 @@ router.post('/custom-items/:itemId/promote', requireAdmin, async (req, res) => {
   res.json({ item })
 })
 
+router.post('/custom-items/:itemId/replace', requireAdmin, async (req, res) => {
+  const schema = z.object({
+    targetItemId: z.string().trim().min(1),
+    targetSourceType: z.enum(['template', 'user', 'asset']).optional().default('user'),
+  })
+  const parsed = schema.safeParse(req.body)
+  if (!parsed.success) return res.status(400).json({ error: 'bad_request' })
+
+  const sourceItem = await findLibraryItemForReplacement(req.params.itemId)
+  if (!sourceItem?.src) return res.status(404).json({ error: 'source_not_found' })
+
+  const targetItem = await findLibraryItemForReplacement(parsed.data.targetItemId, parsed.data.targetSourceType)
+  if (!targetItem?.src) return res.status(404).json({ error: 'target_not_found' })
+  if (sourceItem.src === targetItem.src && (sourceItem.label || '') === (targetItem.label || '')) {
+    return res.status(409).json({ error: 'same_target' })
+  }
+
+  const result = await replaceUploadSourceReferences({
+    fromSrc: sourceItem.src,
+    toSrc: targetItem.src,
+    toLabel: targetItem.label || '',
+  })
+
+  res.json({
+    ok: true,
+    updatedRows: result.updatedRows || 0,
+    sourceItem,
+    targetItem,
+  })
+})
+
 router.post('/tierlists/:tierListId/promote-items', requireAdmin, async (req, res) => {
   const schema = z.object({
     topicId: z.string().min(1),