feat: implement community editing with audit logs and user attribution

Add created/updated tracking and edit logs to all wiki tables
Restrict create/update/delete operations to verified users
Display edit metadata on frontend detail and list views

frontend/src/components/EditMeta.vue

@@ -0,0 +1,20 @@
+<script setup lang="ts">
+import type { EditInfo } from '../services/api';
+
+defineProps<{
+  entity: EditInfo;
+}>();
+
+function formatDateTime(value: string): string {
+  return new Intl.DateTimeFormat('zh-CN', {
+    dateStyle: 'medium',
+    timeStyle: 'short'
+  }).format(new Date(value));
+}
+</script>
+
+<template>
+  <p class="edit-meta">
+    最后编辑：{{ entity.updatedBy?.displayName ?? '系统' }} / {{ formatDateTime(entity.updatedAt) }}
+  </p>
+</template>