diff --git a/apps/waterfall-wiki/src/lib/api-documentation.ts b/apps/waterfall-wiki/src/lib/api-documentation.ts
index e5096d4..342bf7e 100644
--- a/apps/waterfall-wiki/src/lib/api-documentation.ts
+++ b/apps/waterfall-wiki/src/lib/api-documentation.ts
@@ -68,7 +68,7 @@ export const apiDocuments:Record<string,readonly string[]>={
   "/api/preview": [
     "轻量图片预览",
     "GET, HEAD",
-    "查询参数：source（必填，本站静态栅格图片路径，或 /api/media/<UUID>，可带 ?variant=poster；作为查询值时必须 URL 编码）；width（可选，240 / 480 / 960 / 1280，默认 480）。不接受任意远程图片地址。支持 If-None-Match。",
+    "查询参数：source（必填，本站静态栅格图片路径，或 /api/media/<UUID>，可带 ?variant=poster；作为查询值时必须 URL 编码）；width（可选，240 / 480 / 960 / 1280，默认 480）。高清导出使用 profile=export 且 width=2160：WebP 质量95，不按常规缩略图预算缩小，不放大小原件；其他 profile 或尺寸组合返回400。不接受任意远程图片地址。支持 If-None-Match。",
     "WebP 图片；包含 ETag；缓存命中可返回 304；HEAD 无正文。",
     "GET /api/preview?source=%2Fapi%2Fmedia%2F<UUID>&width=480",
     "400：参数不合法；404：图片不存在；503：预览暂不可用。"
diff --git a/apps/waterfall-wiki/tests/integration.test.ts b/apps/waterfall-wiki/tests/integration.test.ts
index 9e63fd9..717abf7 100644
--- a/apps/waterfall-wiki/tests/integration.test.ts
+++ b/apps/waterfall-wiki/tests/integration.test.ts
@@ -42,6 +42,8 @@ test('real PostgreSQL + S3 notes, flat tags, resource sharing and video processi
   await db().query("INSERT INTO contribution_events(id,kind,subject_type,amount) VALUES($1,'test.import','asset',2),($2,'test.edit','post',3)",[randomUUID(),randomUUID()]);assert.equal((await request('/api/feed')).contributions.reduce((n:number,c:{total:number})=>n+c.total,0),5);
   const img=await fetch(base+'/api/media/'+first.assets[0],{headers:{Range:'bytes=0-9'}});assert.equal(img.status,206);assert.equal((await img.arrayBuffer()).byteLength,10);
   const lightweight=await fetch(base+'/api/preview?source='+encodeURIComponent('/api/media/'+first.assets[0])+'&width=480');assert.equal(lightweight.status,200);assert.match(lightweight.headers.get('content-type')||'',/image\/webp/);assert.ok((await lightweight.arrayBuffer()).byteLength<=100000);
+  const highQuality=await fetch(base+'/api/preview?source='+encodeURIComponent('/api/media/'+first.assets[0])+'&width=2160&profile=export');assert.equal(highQuality.status,200);assert.match(highQuality.headers.get('content-type')||'',/image\/webp/);const exportMeta=await sharp(Buffer.from(await highQuality.arrayBuffer())).metadata();assert.equal(exportMeta.width,160);assert.equal(exportMeta.height,220);
+  assert.equal((await fetch(base+'/api/preview?source='+encodeURIComponent('/api/media/'+first.assets[0])+'&width=2160')).status,400);
   const textEntry=await fetch(base+'/explore/'+reused.id+'?agent_mode=True');assert.equal(textEntry.status,200);assert.match(textEntry.headers.get('content-type')||'',/text\/plain/);assert.ok((await textEntry.text()).includes(first.assets[0]));
   assert.equal((await fetch(base+'/images/lines/missing')).status,404);assert.equal((await fetch(base+'/p/'+reused.slug)).status,200);
   for(const sound of [true,false]){