upgrade: adopt V8.21.3 (V8.13→8.21.3: P5 SFTP/S3, P6 multilingual, editor overhaul, enterprise hardening)

Overlay ~150 upstream items onto our V8.12 base, preserving trade-pro
theme, registry tests, and design docs. Re-applied our patch set
(discovery/env_for/blocks.css/type-mapping/theme_color/frontend entries,
test_theme_pro_v3 mods) — all anchors survived upstream evolution.

New platform enhancement (fixes upgrade-introduced regression):
multilingual.site_locale now honors settings_json.locale, plus
PUT /api/i18n/sites/{id}/locale — standalone English sites get
<html lang='en'> under the V8.15 locale-rewrite pipeline.

compose: adopt V8.21.3 (image 8.21.3-dev.1, /api/ready probes, MySQL/S3
env) with project name pinned to siteforge-v8-10 (data volumes).

Tests: 356 passed / 11 failed — all 11 confirmed pre-existing in
pristine V8.21.3 on this host (10 upstream Windows env + our build test
now green after locale fix). Patch registry updated in plan doc.

Co-Authored-By: Claude Code <noreply@anthropic.com>

integrations/art-design-pro/src/views/siteforge/MigrationCenter.vue

@@ -19,18 +19,20 @@
  </div>
 </template>
 <script setup lang="ts">
-import {ref,onMounted} from 'vue'
+import {watch,ref,onMounted} from 'vue'
 import {ElMessage,ElMessageBox} from 'element-plus'
+import {preferredSite,rememberSite,sfApi} from './_shared'
 interface Site{id:string;name:string}
 interface Report{input:number;mapped:number;errors:Array<{row:number;error:string}>;warnings:Array<{row:number;issue:string}>;preview:Array<{title:string;type:string;route:string;seo_title:string}>}
 const sites=ref<Site[]>([]),siteId=ref(''),platform=ref('wordpress-rest'),file=ref<File|null>(null),report=ref<Report|null>(null),loading=ref(false),csrf=ref(''),reviews=ref<Array<{id:string;issue:string;platform:string;row_number:number}>>([])
 function setFile(event:Event){file.value=(event.target as HTMLInputElement).files?.[0]||null;report.value=null}
-async function request(url:string,init:RequestInit={}){const r=await fetch(url,{...init,credentials:'same-origin'});const data=await r.json();if(!r.ok)throw Error(data.detail||'请求错误');return data}
+async function request(url:string,init:RequestInit={}){return sfApi<any>(url,init)}
 async function submit(mode:'preview'|'import'){if(!siteId.value||!file.value)return ElMessage.warning('请选网站和 JSON 文件');const body=new FormData();body.append('file',file.value);body.append('platform',platform.value);if(mode==='import')body.append('conflict','skip');loading.value=true;try{const data=await request(`/api/migrations/sites/${siteId.value}/${mode}`,{method:'POST',headers:{'X-SiteForge-CSRF':csrf.value},body});if(mode==='preview')report.value=data as Report;else{ElMessage.success(`导入完成：${data.result.imported} 条`);report.value=null;await loadReviews()}}catch(e:any){ElMessage.error(e.message)}finally{loading.value=false}}
 async function preview(){await submit('preview')}
 async function commit(){if(!report.value||report.value.errors.length)return;try{await ElMessageBox.confirm('导入后会写入网站数据库。复杂字段保留人工核对标记，是否继续？','确认导入');await submit('import')}catch{}}
 async function loadReviews(){if(!siteId.value)return;try{reviews.value=(await request(`/api/migrations/sites/${siteId.value}/reviews`)).items}catch(e:any){ElMessage.error(e.message)}}
 async function resolve(id:string){try{const result=await ElMessageBox.prompt('请输入实际核对结果或修正措施，至少12字','迁移复核',{inputValidator:(v:string)=>v.trim().length>=12||'请说明具体处理情况'});await request(`/api/migrations/sites/${siteId.value}/reviews/${id}/resolve`,{method:'POST',headers:{'Content-Type':'application/json','X-SiteForge-CSRF':csrf.value},body:JSON.stringify({resolution:result.value})});ElMessage.success('已保存复核记录');await loadReviews()}catch(e:any){if(e!=='cancel')ElMessage.error(e.message)}}
-onMounted(async()=>{try{csrf.value=(await request('/api/auth/me')).csrf;sites.value=await request('/api/sites');siteId.value=sites.value[0]?.id||'';await loadReviews()}catch(e:any){ElMessage.error(e.message)}})
+watch(siteId,(id)=>rememberSite(id))
+onMounted(async()=>{try{csrf.value=(await request('/api/auth/me')).csrf;sites.value=await request('/api/sites');siteId.value=preferredSite(sites.value);await loadReviews()}catch(e:any){ElMessage.error(e.message)}})
 </script>
 <style scoped>.heading{margin-bottom:20px}.heading h2{margin:0;font-size:24px}.heading p{color:var(--el-text-color-secondary)}</style>