Fix China app installs and wire the CN AI stack into Install > AI

Offline installs ship no pacman sync db, so yay resolved official
repo dependencies as AUR packages and every catalog install failed;
omarchy-cn-app-install now runs a full -Syu first (verified end to
end: WeChat builds and installs in the VM). Kimi Code gains a real
installer command reused by the harness registry, the default-agent
path, and new Install > AI entries (Kimi Code, Deep Code, AI Hub),
and the AI Hub wizard offers to launch native harnesses immediately
so their official CLI login runs, matching how Claude Code works.

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

bin/omarchy-cn-ai-setup

@@ -40,7 +40,10 @@ proto=$(cn_ai_harness_field "$harness" protocol)
 if [[ $proto == "native" ]]; then
   omarchy-cn-ai-profile-create "$name" "$harness" "$provider" "$model"
   omarchy-cn-ai-profile-use "$name"
-  echo "$harness 自管鉴权：首次启动时按其官方流程登录/配置"
+  echo "$harness 自管鉴权：首次启动时在 CLI 内完成官方登录"
+  if gum confirm "立即启动并完成官方登录？"; then
+    exec omarchy-cn-ai-launch "$name"
+  fi
   echo "完成。启动: omarchycn ai launch"
   exit 0
 fi