One-click convert between vanilla Omarchy and OmarchyCN

omarchy-cn-convert turns a package-based install into OmarchyCN in one
curl-able run: registry key + [omarchycn] repo, --ask=4 swap onto the
cn-built packages (Chinese menu/bindings and OMARCHY CN branding ride
the settings tree), [omarchy] mirror line, zh_CN locale, fcitx5-rime
seeding, CN Arch mirrors, and a plymouth rebrand, recording pre-state
in /var/lib/omarchycn/convert-state. omarchy-cn-revert restores that
state symmetrically and survives user-removed packages, self-deletion
mid-swap, and cosmetic plymouth failures after the state is cleared.
Checkout installs are refused toward the overlay.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019hLK3wsDuKVAC37GgDqg6H

default/omarchy/omarchy-menu.jsonc

@@ -418,5 +418,6 @@
   "omarchycn.diagnostics.mirror-fix": {"icon":"󰇧","label":"镜像修复","action":"omarchy-launch-floating-terminal-with-presentation 'omarchy-cn-doctor mirror --fix'"},
   "omarchycn.diagnostics.ime": {"icon":"󰌌","label":"输入法状态","action":"omarchy-launch-floating-terminal-with-presentation omarchy-cn-ime-status"},
   "omarchycn.update": {"icon":"","label":"更新","when":"[[ -f ~/.local/state/omarchycn/overlay-manifest ]]","action":"omarchy-launch-floating-terminal-with-presentation omarchy-cn-update"},
+  "omarchycn.revert": {"icon":"󰕍","label":"回退为原版 Omarchy","when":"[[ -f /var/lib/omarchycn/convert-state ]]","action":"omarchy-launch-floating-terminal-with-presentation omarchy-cn-revert"},
   "omarchycn.about": {"icon":"","label":"关于","action":"omarchy-launch-floating-terminal-with-presentation omarchy-cn-status"},
 }