Switch the region under Setup > Region, and offer China Apps

omarchy region cn|global switches an installed machine: cn upgrades,
trusts ArchLinuxCN through the rendered China config, records the
marker and links the developer mirrors, then refreshes pacman;
global undoes only what Omarchy made. The developer mirrors reach
new sessions only, so a terminal switch offers to log out.

Install > China Apps, shown only in China, installs WeChat, QQ,
Feishu, DingTalk, Tencent Meeting and WPS Office from the AUR and
sets up Tencent Docs, Yuque and Shimo as web apps.

manual/52-china.md describes the China region.

test/shell.d/menu-test.sh

@@ -284,13 +284,22 @@ assert(
   'menu always exposes every supported browser, terminal, and editor under Defaults'
 )
 assert(!defaultById['install.ai.crush'], 'menu removes Crush from Install > AI')
+const regionEntries = defaultItems.filter(item => item.parent === 'setup.region')
+assert(
+  regionEntries.map(item => item.label).join('\0') === 'Global\0China'
+    && regionEntries.every(item => item.checked.includes(`== \"${item.label}\"`) && !item.when)
+    && defaultById['setup.region.global'].action.includes('omarchy-region global')
+    && defaultById['setup.region.china'].action.includes('omarchy-region cn'),
+  'menu offers Global and China under Setup > Region'
+)
 // Software you already have keeps its place in Install, dimmed rather than
 // dropped, so the list reads as a catalog of what Omarchy can install.
 // Chromium Account is the sole Install row with anything left to hide for, so
 // any other `when:` here is a row that went back to vanishing once installed.
 assertDeepEqual(
   defaultItems
-    .filter(item => item.id.startsWith('install.') && item.action && item.when)
+    // China Apps rows hide by region, not because the software is there.
+    .filter(item => item.id.startsWith('install.') && item.action && item.when && item.when !== '[[ "$(omarchy-region)" == "China" ]]')
     .map(item => item.id),
   ['install.service.chromium-account'],
   'menu never hides an Install row because the software is already there'