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-agent

@@ -101,7 +101,7 @@ pi)
   ;;
 kimi)
   command=(kimi)
-  [[ -n ${prompt:-} ]] && command+=("$prompt")
+  [[ -n ${prompt:-} ]] && command+=(--prompt "$prompt")
   ;;
 deepcode)
   command=(deepcode)