feat: add CODEX_PATH env var for custom binary path (macOS Gatekeeper fix)

[glenhsu]

Summary

Adds CODEX_PATH environment variable support so users can override the codex binary path — a fix for macOS Gatekeeper silently deleting the SDK-bundled binary.

Changes

.env.example

• Added CODEX_PATH env var with documentation (optional override for codex binary path)
• Added OMLX_API_KEY as commented example for custom provider setup

src/codex-session.ts (resetCodexClient)

• Checks for process.env["CODEX_PATH"] and passes it as codexPathOverride to the Codex constructor
• Refactored Codex initialization to use an options object approach

README.md

• Added Troubleshooting section with two common issues:
  • ❌ "Missing environment variable: OMLX_API_KEY"
  • ❌ "Failed to spawn Codex CLI: EACCES" (macOS Gatekeeper)

Why

macOS Gatekeeper on Sequoia silently quarantines and deletes the SDK-bundled codex binary at node_modules/@openai/codex-darwin-arm64/vendor/aarch64-apple-darwin/codex/ — no UI prompt, no entry in System Settings. The SDK then fails with EACCES.

With CODEX_PATH, users point to their homebrew-installed binary (/opt/homebrew/bin/codex) and bypass Gatekeeper entirely.

Also includes a complementary setup guide with full step-by-step instructions: https://github.com/glenhsu/telecodex-codex-cli-setup

[gugglegum]

Dude, you beat me to it by 48 minutes. :) I think you forgot to commit the changes to src/codex-session.ts, and I think my version is better because the option goes through the config and is covered by tests.