feat: 관리자 대체 아이템 전용 필터 추가

backend/src/routes/admin.js

@@ -55,6 +55,8 @@ const {
   clearImageOptimizationJobs,
   cleanupMissingUploadReferences,
   replaceUploadSourceReferences,
+  updateCustomItemDisplayReferences,
+  clearCustomItemReplacement,
 } = require('../db')
 const { requireAdmin } = require('../middleware/auth')
 const { createMemoryUpload, writeOptimizedImage, getImageOptimizationQueueState } = require('../lib/image-storage')
@@ -358,7 +360,7 @@ router.get('/custom-items', requireAdmin, async (req, res) => {
     page: z.coerce.number().int().min(1).optional().default(1),
     limit: z.coerce.number().int().min(1).max(200).optional().default(50),
     filter: z
-      .enum(['library', 'all', 'user', 'template', 'asset', 'thumbnail', 'avatar', 'unused-user', 'unused-admin'])
+      .enum(['library', 'all', 'user', 'template', 'asset', 'thumbnail', 'avatar', 'unused-user', 'replaced-user', 'unused-admin'])
       .optional()
       .default('library'),
   })
@@ -837,6 +839,11 @@ router.post('/custom-items/:itemId/replace', requireAdmin, async (req, res) => {
     toLabel: targetItem.label || '',
     updateCustomItemsBySrc: false,
   })
+  const displayResult = await updateCustomItemDisplayReferences({
+    itemId: sourceItem.id,
+    src: targetItem.src,
+    label: targetItem.label || '',
+  })
   await markCustomItemReplaced({
     itemId: sourceItem.id,
     replacedByItemId: targetItem.id || '',
@@ -846,12 +853,31 @@ router.post('/custom-items/:itemId/replace', requireAdmin, async (req, res) => {
 
   res.json({
     ok: true,
-    updatedRows: result.updatedRows || 0,
+    updatedRows: (result.updatedRows || 0) + (displayResult.updatedRows || 0),
     sourceItem,
     targetItem,
   })
 })
 
+router.post('/custom-items/:itemId/restore', requireAdmin, async (req, res) => {
+  const sourceItem = await findCustomItemById(req.params.itemId)
+  if (!sourceItem?.id) return res.status(404).json({ error: 'not_found' })
+  if (!sourceItem.replacedAt) return res.status(409).json({ error: 'not_replaced' })
+
+  const restored = await updateCustomItemDisplayReferences({
+    itemId: sourceItem.id,
+    src: sourceItem.src,
+    label: sourceItem.label || '',
+  })
+  await clearCustomItemReplacement(sourceItem.id)
+
+  res.json({
+    ok: true,
+    restoredRows: restored.updatedRows || 0,
+    item: await findCustomItemById(sourceItem.id),
+  })
+})
+
 router.post('/tierlists/:tierListId/promote-items', requireAdmin, async (req, res) => {
   const schema = z.object({
     topicId: z.string().min(1),