v0.8.1 — panel scroll fix

• Fix: the panel could not scroll in Harness (content below the MV canvas unreachable, and the header with the 外观 button could disappear). Harness hosts plugin panels in a centre column that is display:flex; flex-direction:column; overflow:hidden; the panel root grew to the column height with its content overflowing, so the wheel did nothing, and focus() / scrollIntoView() (stage focus, calibration line follow) scrolled the hidden column instead, pushing the header out of view with no way back. The panel root is now its own scroll container (flex: 1 1 auto; min-height: 0; height: 100%; overflow-y: auto), is pinned to the clipping ancestor if a host wraps it in an unsized block, and resets programmatic scrolls of that ancestor. Sticky sidebar / player bar / tmux bar / status line now stick inside the panel in all skins. Wheel over the MV canvas scrolls the panel.
  修复：在 Harness 里面板无法滚动、画面下方内容够不到、顶部「外观」按钮消失。面板现在自己滚动，三套外观都适用。
• Preview: ?host=1|wrap|art mirrors the Harness frame; tools/ui-preview/scroll-check.mjs checks wheel / bottom / back-to-top in every skin.

Install: npm i -g @ljwei-stak/dsh-mv-cli@0.8.1 · sha256 of the tgz is attached.