release: v1.4.0 — 标签系统、操作日志扩展与文档截图更新

- 每用户标签与彩色打标，图库 OR/AND 筛选与批量打标
- 操作日志记录登录、删除、设置与标签操作
- API 标签/打标接口；README 与文档站截图同步

docs-site/en/guide/storage.md

@@ -18,6 +18,8 @@ PicHost supports **local disk** and **S3-compatible object storage** (Cloudflare
 
 All **keys** start with `images/`. The upload API does **not** accept a `folder` parameter.
 
+**Classification** uses per-user **tags** in SQLite (`tags` / `image_tags`); disk paths are unchanged. See [API](./api.md#6-tags).
+
 ## Adding a backend
 
 1. Sign in as admin → **Storage** → **Add backend**.
@@ -54,7 +56,9 @@ Copied links use **IMAGE_BASE_URL**. “Hide folder prefix” may shorten URLs;
 ## Usage & gallery filter
 
 - Per-backend usage on the Storage page
-- Gallery filters by **storage backend** and **upload source**; grid/list view toggle; click a thumbnail for the detail modal (dimensions, storage path, link formats)
+- Gallery filters by **storage backend**, **upload source**, and **tags**; grid/list view toggle; click a thumbnail for the detail modal (dimensions, storage path, tags, link formats)
+
+![Gallery grid](/screenshots/gallery.png) ![Gallery list](/screenshots/gallery-list.png) ![Image detail](/screenshots/gallery-detail.png)
 
 ## Backup & migration (v1.3.0+)