fix(ci): remove API keys from agent env when api-proxy is enabled

[Claude]

When api-proxy is enabled, API keys were being passed to both the agent container and the api-proxy sidecar, defeating the security isolation model where credentials should only exist in the sidecar.

Changes

• Removed CODEX_API_KEY and OPENAI_API_KEY from agent environment block in smoke-codex.lock.yml
• Kept OPENAI_BASE_URL and ANTHROPIC_BASE_URL to route requests through api-proxy

Flow

# Before (insecure - keys exposed to agent)
env:
  CODEX_API_KEY: ${{ secrets.CODEX_API_KEY }}
  OPENAI_API_KEY: ${{ secrets.CODEX_API_KEY }}
  OPENAI_BASE_URL: http://api-proxy:10000

# After (secure - keys isolated in sidecar)
env:
  OPENAI_BASE_URL: http://api-proxy:10000
  ANTHROPIC_BASE_URL: http://api-proxy:10001

The awf CLI receives keys from host environment via sudo -E → reads from process.env → passes only to api-proxy container (not agent) → api-proxy injects auth headers.

This restores the documented security model: agent cannot access credentials, only routes to proxy.

[Copilot]

Pull request overview

This PR updates the Codex smoke-test GitHub Actions workflow to avoid exposing LLM API credentials to the agent container when the API proxy sidecar is used, aligning CI with the intended credential-isolation model.

Changes:

• Removes CODEX_API_KEY and OPENAI_API_KEY from the Codex execution step environment.
• Keeps OPENAI_BASE_URL / ANTHROPIC_BASE_URL set to route requests via the api-proxy sidecar.

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[Copilot]

Removing both CODEX_API_KEY and OPENAI_API_KEY here means the awf process no longer has an API key in its environment to pass into the api-proxy sidecar (awf only reads OpenAI credentials from process.env.OPENAI_API_KEY). Since this step still forces OPENAI_BASE_URL to http://api-proxy:10000, Codex/OpenAI calls will likely hit the sidecar without auth headers and fail (e.g., 401). Consider keeping OPENAI_API_KEY available to the awf invocation while preventing it from being forwarded into the agent container (e.g., stop using --env-all and pass only the needed env vars explicitly, or add filtering so OPENAI_API_KEY/CODEX_API_KEY are not propagated to the agent when api-proxy is enabled).

Suggested change

	GITHUB_STEP_SUMMARY: ${{ env.GITHUB_STEP_SUMMARY }}
	GITHUB_STEP_SUMMARY: ${{ env.GITHUB_STEP_SUMMARY }}
	OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
	CODEX_API_KEY: ${{ secrets.CODEX_API_KEY }}