[5/8] Rename Python SDK package to openai-codex

[aibrahim-oai]

Why

The SDK should publish under the reserved public distribution name openai-codex, and its import module should match that name in the Python style. Since package names can contain hyphens but import modules cannot, the public import path becomes openai_codex.

Keeping the rename separate from the public API surface change makes the naming change easy to review and avoids mixing it with API curation.

What

• Rename the SDK distribution from openai-codex-app-server-sdk to openai-codex.
• Rename the import package from codex_app_server to openai_codex.
• Keep the runtime wheel as the separate openai-codex-cli-bin dependency.
• Update docs, examples, notebooks, artifact scripts, lockfile metadata, and tests for the new distribution/module names.

Stack

1. [1/8] Pin Python SDK runtime dependency #21891 [1/8] Pin Python SDK runtime dependency
2. [2/8] Generate Python SDK types from pinned runtime #21893 [2/8] Generate Python SDK types from pinned runtime
3. [3/8] Run Python SDK tests in CI #21895 [3/8] Run Python SDK tests in CI
4. [4/8] Define Python SDK public API surface #21896 [4/8] Define Python SDK public API surface
5. This PR [5/8] Rename Python SDK package to openai-codex
6. [6/8] Add high-level Python SDK approval mode #21910 [6/8] Add high-level Python SDK approval mode
7. [7/8] Add Python SDK app-server integration harness #22014 [7/8] Add Python SDK app-server integration harness
8. [8/8] Add Python SDK Ruff formatting #22021 [8/8] Add Python SDK Ruff formatting

Verification

• Updated package metadata and public API tests to assert the distribution and import names.