Localize update confirmation and first-run notifications

The update prompt speaks Chinese and points What's new at the
OmarchyCN releases page; the Wi-Fi, update, keybindings, dictation,
and default-agent first-run notices follow.

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

install/user/first-run/welcome.sh

@@ -1,5 +1,5 @@
 # Real newlines, not a literal \n: the card renders the body as it arrives, and
 # elides past three lines.
-omarchy-notification-send -u critical -g  "Learn Keybindings" \
-  $'Super + K for cheatsheet.\nSuper + Space for Omarchy Menu.' \
+omarchy-notification-send -u critical -g  "学习快捷键" \
+  $'Super + K 查看快捷键表。\nSuper + Space 打开 Omarchy 菜单。' \
   --exec omarchy-menu-keybindings