v0.14.0 — Chromium app window for the detached notepad

Open the detached notepad as a Chromium app-mode window instead of a normal browser tab.

• The default detached window is now launched by the Host with the local Edge / Chrome --app=URL form: no tabs, no address bar, a dedicated window with its own taskbar entry and independent minimize / restore.
• Settings → Notepad → Detached window gains a Window form choice: app window (default) or system browser window. If no Chromium browser is found, the client falls back to the previous browser-window path.
• Every app window uses a dedicated temporary Chromium profile (--user-data-dir), --window-size, --no-first-run and --no-default-browser-check, so it does not restore unrelated tabs or attach to the user’s main browser session.
• A duplicate request while the detached page is alive returns the existing window instead of spawning another one.
• A page favicon is served to give the app window its notepad icon.
• Note: this is a dedicated Chromium window, not a DSH Electron BrowserWindow. DSH’s main process denies window.open and exposes no window-creation IPC to plugins; a true Electron window needs a desktop-side core change. The README documents this boundary.

独立窗口改为 Chromium 应用窗口，不再默认打开普通浏览器标签页。

• 默认由宿主调用本机 Edge / Chrome 的 --app=URL，打开无标签页、无地址栏的独立应用窗口，有自己的任务栏窗口和最小化 / 还原。
• 设置页新增「窗口形式」：独立应用窗口（默认）/ 系统浏览器窗口；找不到浏览器时自动回退到原来的浏览器窗口。
• app 模式使用独立的临时 Chromium profile、窗口尺寸、--no-first-run 和 --no-default-browser-check，不会恢复无关标签页或附加到用户主浏览器会话。
• 独立窗口仍由插件回环服务 + 随机 token 提供；DSH 最小化 / 关闭页面不影响它，关闭窗口或点「收回面板」后浮窗自动恢复。
• 这不是 DSH 自己的 Electron BrowserWindow：主进程拒绝 window.open 且插件没有创建窗口的 IPC；真正的 BrowserWindow 需要桌面端核心改动，README 已说明边界。