Configure HTTPS agent for proxies (#775)

- Some workflows require you to route openAI API traffic through a proxy
- See
https://github.com/openai/openai-node/tree/v4?tab=readme-ov-file#configuring-an-https-agent-eg-for-proxies
for more details

---------

Co-authored-by: Thibault Sottiaux <tibo@openai.com>
Co-authored-by: Fouad Matin <fouad@openai.com>

codex-cli/package.json

@@ -34,6 +34,7 @@
     "fast-npm-meta": "^0.4.2",
     "figures": "^6.1.0",
     "file-type": "^20.1.0",
+    "https-proxy-agent": "^7.0.6",
     "ink": "^5.2.0",
     "js-yaml": "^4.1.0",
     "marked": "^15.0.7",