feat: add local codex cli provider

[luboszima]

Draft PR for: #1752

• after original issue will be resolved please close this PR.

Description

Motivation: I tried to fix docker-agent to use codex subscription which I am using by local codex-cli.

Tests

tested locally with:

./bin/docker-agent run --exec  ./examples/basic_agent.yaml --model openai-codex/gpt-5.3-codex  "Reply with exactly: ok"

or

./bin/docker-agent run --exec  ./examples/basic_agent.yaml --model openai-codex/gpt-5.4  "Reply with exactly: ok" 

Test output:

--- Agent: root ---
ok%  

[aheritier]

needs to be rebased (at the minimum). Moving it to draft
OpenAI / Codex looks to be (nowadays) more open than Anthropic which is making this forbidden