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

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

apps/backend/src/collections/Audit/hooks/auditHooks.ts

@@ -8,13 +8,16 @@ import { logDocumentChange } from '@/utilities/auditLogger'
  */
 export const auditChange =
   (collection: string): AfterChangeHook =>
-  async ({ doc, req }) => {
+  async ({ doc, req, context }) => {
     // 跳過 audit 集合本身以避免無限循環
     if (collection === 'audit') return doc
 
+    // Determine operation from context or default to 'update'
+    const operation = (context?.operation as 'create' | 'update' | 'delete') || 'update'
+
     await logDocumentChange(
       req,
-      operation as 'create' | 'update' | 'delete',
+      operation,
       collection,
       doc.id as string,
       (doc.title || doc.name || String(doc.id)) as string,

apps/backend/src/collections/Posts/index.ts

@@ -111,7 +111,7 @@ export const Posts: CollectionConfig<'posts'> = {
                 },
               }),
               label: false,
-              required: true,
+              required: false, // Temporarily disabled for migration
             },
             {
               name: 'excerpt',