cn commands: use OMARCHY_PATH per runtime convention

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QKxGW1raAWaqeU8WdHsMsp

bin/omarchy-cn-version

@@ -4,10 +4,7 @@
 
 set -euo pipefail
 
-OMARCHY_BIN_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)
-ROOT="${OMARCHY_BIN_DIR%/bin}"
-
-upstream=$(<"$ROOT/version")
-release=$(<"$ROOT/cn/release")
+upstream=$(<"$OMARCHY_PATH/version")
+release=$(<"$OMARCHY_PATH/cn/release")
 
 echo "${upstream}-cn.${release}"