docs: add Claude Code routing via CLIProxyAPI demo

[Jiliac]

Summary

Adds a reproducible demo for routing Claude Code across Codex subscription models through Plano while delegating protocol translation and OAuth handling to a local CLIProxyAPI upstream.

The data path is:

Claude Code -> Plano preference routing -> CLIProxyAPI /v1/messages -> Codex OAuth

This keeps Plano focused on preference routing and model aliases, while CLIProxyAPI owns the Anthropic-to-Codex compatibility layer.

Included

• Plano v0.4 config with three Anthropic-compatible upstream models:
  • gpt-5.6-sol for diagnosis-only deep reasoning
  • gpt-5.6-terra for implementation work
  • gpt-5.6-luna for quick developer utilities
• Claude family fallback aliases: Fable→Sol, Opus→Terra, Sonnet/Haiku→Luna
• Loopback-only CLIProxyAPI config example with management disabled
• Small preflight-only claude-plano launcher that:
  • validates loopback binding
  • authenticates /v1/models
  • verifies all required models
  • checks Plano health
  • removes the proxy key before executing Claude Code
• Full setup guide for Homebrew and non-Homebrew installs, Codex OAuth login, local/native startup, Docker production isolation, troubleshooting, rollback, and context-window model naming
• Mock-based launcher tests and structural config/README policy validation

Important boundaries

• CLIProxyAPI is an independent MIT-licensed project, not part of Plano, Anthropic, or OpenAI.
• Public wire model IDs remain unsuffixed. Claude Code client annotations such as [1m] are optional client-side hints and are not CLIProxyAPI model IDs.
• Top-level routing preferences override Claude family alias targets when a route matches; aliases remain initial/fallback targets.
• Native Plano internal listeners are explicitly pinned to loopback in the documented development command. Docker isolation is recommended for production.
• The public launcher intentionally does not use --dangerously-skip-permissions.

Test plan

cd demos/llm_routing/claude_code_cliproxy
./test.sh
shfmt -i 2 -ci -d claude-plano test.sh tests/*.sh
shellcheck claude-plano test.sh tests/*.sh
ruby -c validate_configs.rb
ruby validate_configs.rb config.yaml cliproxyapi.conf.example

All checks pass locally. Tests use mocks and do not require credentials, OAuth login, or model inference.

Validation performed during development

The integration was also exercised end-to-end outside the committed test suite with Claude Code single-turn, multi-turn, streaming/non-streaming, file tools, Explore subagents, all four Claude alias families, hosted Sol/Terra/Luna routing, and direct-proxy fallback.

🤖 Generated with Claude Code

[Jiliac]

I'm my usage, this has proved unstable. So I'm closing the PR.