菜单栏合并时点击弹出状态总览，可切到各项详情（#2）

- 合并模式点击图标不再直接打开主窗口，改为弹出面板：顶部标签在总览与菜单栏开启的各项之间切换
- 总览每项一行：数值、状态、走势，偏高时变色；点一行进入该项完整详情，与每项独立时的弹窗共用 PopoverDetail
- 切到某一项时 openPopover 跟着切换，采样范围与单项弹窗一致；面板打开期间每秒刷新
- 合并面板最小高度减半，项目少时不留空白；设置里的弹窗区块选项在合并模式下也可用
- 电池状态文案合成 BatteryStatus.stateText；--show-panel overview 用于调试

ARCHITECTURE.md

@@ -135,7 +135,10 @@ pieces of read-mostly logic in `Cleaner/DiskTools.swift`, each testable without
 
 `MenuBarController` owns the status items. In the *separate* layout every enabled metric gets
 its own `NSStatusItem` (created in reverse so they read left to right) and opens a 320 pt
-popover for that metric; in the *combined* layout a single item opens the main window.
+popover for that metric; in the *combined* layout a single item opens `CombinedPopoverView`: a status
+overview with one row per enabled metric, plus tabs that switch to each metric's full popover content
+(`PopoverDetail`, shared with the separate layout). While a detail tab is showing, `AppModel.openPopover`
+is set to that metric so sampling matches the standalone popover.
 
 Popovers are borderless, non-activating `NSPanel`s. The SwiftUI tree is created on open and
 destroyed on close, so a hidden popover costs nothing. Height comes from measuring a flat,