docs: clarify Claude Code support page

Author: masterkain

docs-site/src/content/docs/clients/claude-code.mdx

@@ -9,9 +9,11 @@ description: Claude Code is intentionally not a supported Codex Pooler client; u
 
 Claude Code is not supported by Codex Pooler.
 
+This page exists to make that explicit and point you at the setup paths we actually maintain.
+
 ## Use a supported client instead
 
-Choose one of the clients with a documented setup path:
+Choose one of these instead:
 
 - [Codex CLI](/clients/codex-cli/)
 - [OpenCode](/clients/opencode/)