Fix kimi install error masking, prompt flag, and setup default hop

The official installer downloads to a temp file so curl failures
cannot be masked by the pipe; Kimi prompts use --prompt per the CLI
reference; the AI Hub wizard now offers omarchy-cn-ai-default for
claude-code/codex profiles so the combo really becomes the default
agent.

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

bin/omarchy-cn-ai-setup

@@ -73,4 +73,10 @@ fi
 
 rm -f "$profile_file.omarchycn-prev"
 omarchy-cn-ai-profile-use "$name"
+
+if [[ $harness == "claude-code" || $harness == "codex" ]]; then
+  if gum confirm "设为系统默认 Agent（Super+Shift+Ctrl+A）？"; then
+    omarchy-cn-ai-default "$name"
+  fi
+fi
 echo "完成。启动: omarchycn ai launch"