[5/6] Rename Python SDK package to openai-codex

[aibrahim-oai]

Stack

• [1/6] [1/6] Pin Python SDK runtime dependency #21891 Pin Python SDK runtime dependency
• [2/6] [2/6] Generate Python SDK types from pinned runtime #21893 Generate Python SDK types from pinned runtime
• [3/6] [3/6] Run Python SDK tests in CI #21895 Run Python SDK tests in CI
• [4/6] [4/6] Define Python SDK public API surface #21896 Define Python SDK public API surface
• [5/6] [5/6] Rename Python SDK package to openai-codex #21905 Rename Python SDK package to openai-codex
• [6/6] [6/6] Default Python SDK approval policy to never #21910 Default Python SDK approval policy to never

This PR is the fifth change in the stack, on top of #21896.

Why

The published Python SDK should use the reserved public distribution name openai-codex, and the import module should match that public shape as closely as Python allows. Since hyphens are not valid import identifiers, the import module is openai_codex.

Keeping this as a separate PR leaves #21896 focused on the public API shape and makes this package/module rename easy to review on its own.

What changed

• Rename the SDK distribution from openai-codex-app-server-sdk to openai-codex.
• Rename the import package from codex_app_server to openai_codex without adding a compatibility shim.
• Keep the separate runtime dependency as openai-codex-cli-bin.
• Update SDK docs, examples, notebooks, artifact scripts, lockfile metadata, and tests for the new package/module names.

Verification

• git diff --check
• CI is running on this PR.