docs: add Supporting Other CLIs section

[UnaiAlias]

Summary

• Adds new Supporting Other CLIs section in the docs navigation (after User Interfaces)
• Three new pages covering how to use the Alias API with third-party scaffoldings:
  • Claude Code — requires a proxy (1rgs/claude-code-proxy) to translate Anthropic → OpenAI-compatible format
  • Codex CLI — direct OpenAI-compatible setup, no proxy needed
  • OpenCode — config file and env var approaches
• Each page includes a danger admonition warning about third-party data privacy and a warning disclaimer that Alias does not provide support for these integrations
• API key acquisition documented for both cybersecurityai.php (CAI PRO) and aliasLLMs.php (alias2-mini)

Test plan

• Pages render correctly at http://localhost:8088/other_cli/claude_code/
• Pages render correctly at http://localhost:8088/other_cli/codex/
• Pages render correctly at http://localhost:8088/other_cli/opencode/
• Warning banners display as red/orange danger blocks
• Navigation section appears after User Interfaces in sidebar