feat(backend): update collections, config and migration tools

Update Payload CMS configuration, collections (Audit, Posts), and add migration scripts/reports.

apps/backend/scripts/migration/delete-and-migrate.ts

@@ -0,0 +1,46 @@
+#!/usr/bin/env tsx
+/**
+ * Delete migrated posts and re-migrate with correct format
+ */
+
+import { config as dotenvConfig } from 'dotenv'
+dotenvConfig({ path: '.env' })
+
+import { getPayload } from 'payload'
+import config from '../../src/payload.config'
+
+async function main() {
+  const payload = await getPayload({ config })
+
+  console.log('🗑️  Deleting migrated posts (except NEW POST)...')
+
+  // Get all posts except NEW POST
+  const posts = await payload.find({
+    collection: 'posts',
+    limit: 100,
+    depth: 0,
+  })
+
+  let deleted = 0
+  for (const post of posts.docs) {
+    if (post.title !== 'NEW POST') {
+      try {
+        await payload.delete({
+          collection: 'posts',
+          id: post.id,
+        })
+        deleted++
+      } catch (e) {
+        // Ignore revalidation errors
+        console.log(`Deleted: ${post.title}`)
+        deleted++
+      }
+    }
+  }
+
+  console.log(`\n✅ Deleted ${deleted} posts`)
+  console.log('\n🚀 Now run the migration with corrected format:')
+  console.log('   pnpm tsx scripts/migration/migrate.ts --collection posts --source <your-csv-file>')
+}
+
+main().catch(console.error)