Feature idea: direct "Download" action on deliverable cards

[knight-ni]

Summary / 概述

Deliverable cards (deliverables/presented) currently offer only Preview in sidebar / Show file location / More open with. There is no direct way to download the delivered file itself from the card — users must detour through the sidebar preview or a file manager. This is especially inconvenient for large artifacts (report zips) and when accessing the web UI remotely (phone / public tunnel), where the sidebar preview is a poor substitute for actually obtaining the file.

交付卡片（deliverables/presented）目前只有「在侧边栏预览 / 显示文件位置 / 更多打开方式」，没有从卡片直接下载文件本体的入口，取件必须绕行侧边栏或文件管理器。对大体积交付物（报告 zip）以及远程访问（手机/公网隧道）场景尤其不便——侧边栏预览无法替代真正拿到文件。

Proposed behavior / 期望行为

Add a native Download action to the card's action row (an <a download> pointing at the file, e.g. served over an authenticated by-path route), so a delivered file can be fetched in one click.

在卡片操作行原生提供「下载」动作（<a download> 指向文件的鉴权 by-path 路由），一步取件。

Current state / 现状

Verified on dsh-v0.2.1-rc.5: the dsh-client-ui-deliverables card action row has no download entry. We currently inject a download link into the client bundle via a community plugin (structural patch on the card's actions row). Such patches must be replayed after every dsh upgrade and silently break when upstream markup changes — our download button disappeared after this week's 0.2.0-rc.2 → 0.2.1-rc.5 upgrade until the patch was replayed. A native action would let this whole class of workaround retire.

已在 dsh-v0.2.1-rc.5 验证：卡片操作行无下载项。我们目前通过社区插件向前端 bundle 注入下载链接（对卡片 actions 行的结构补丁）。这类补丁在每次 dsh 升级后都需要重放，且上游结构一变即静默失效——本周 0.2.0-rc.2 → 0.2.1-rc.5 升级后下载按钮就丢失了，直到重放补丁才恢复。官方原生提供后，这一整类 workaround 都可以退役。

Environment / 环境

dsh 0.2.1-rc.5 (npm, Linux/WSL), web profile, remote access via tunnel.