fix(agent-document): deserialize tags in listDocuments + null guard in template

- Service layer: map rows with deserializeTags to return string[] not JSON string
- Frontend: add null guard on item.tags.length to prevent render crash when tags is null

Co-authored-by: CodeFree <codefree@chinatelcom.cn>

app/pages/agent-documents/index.vue

@@ -151,7 +151,7 @@ onMounted(() => {
               {{ item.type === 'document' ? '文档' : '记忆' }}
             </span>
             <span class="card-date">{{ new Date(item.updatedAt).toLocaleDateString('zh-CN') }}</span>
-            <span v-if="item.tags.length > 0" class="card-tags">
+            <span v-if="item.tags && item.tags.length > 0" class="card-tags">
               <span v-for="tag in item.tags" :key="tag" class="tag-chip">{{ tag }}</span>
             </span>
           </div>

server/service/agent-document/index.ts

@@ -155,7 +155,7 @@ export async function listDocuments(
   const total = countResult[0]?.count ?? 0;
 
   return {
-    items: rows,
+    items: rows.map((r) => ({ ...r, tags: deserializeTags(r.tags) })),
     total,
     page,
     pageSize,