[5/8] Rename Python SDK package to openai-codex (#21905)

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

## Verification

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

Co-authored-by: Codex <noreply@openai.com>

sdk/python/README.md

@@ -1,4 +1,4 @@
-# Codex App Server Python SDK (Experimental)
+# OpenAI Codex Python SDK (Experimental)
 
 Experimental Python SDK for `codex app-server` JSON-RPC v2 over stdio, with a small default surface optimized for real scripts and apps.
 
@@ -6,7 +6,7 @@ The generated wire-model layer is sourced from the pinned `openai-codex-cli-bin`
 runtime package and exposed as Pydantic models with snake_case Python fields
 that serialize back to the app-server’s camelCase wire format.
 The package root exports the ergonomic client API; public app-server value and
-event types live in `codex_app_server.types`.
+event types live in `openai_codex.types`.
 
 ## Install
 
@@ -25,7 +25,7 @@ automatically.
 ## Quickstart
 
 ```python
-from codex_app_server import Codex
+from openai_codex import Codex
 
 with Codex() as codex:
     thread = codex.thread_start(model="gpt-5")
@@ -76,7 +76,7 @@ uv sync
 python scripts/update_sdk_artifacts.py generate-types
 python scripts/update_sdk_artifacts.py \
   stage-sdk \
-  /tmp/codex-python-release/openai-codex-app-server-sdk \
+  /tmp/codex-python-release/openai-codex \
   --codex-version <codex-release-tag-or-pep440-version>
 python scripts/update_sdk_artifacts.py \
   stage-runtime \
@@ -94,13 +94,13 @@ matrix is `macosx_11_0_arm64`, `macosx_10_9_x86_64`,
 This supports the CI release flow:
 
 - run `generate-types` before packaging
-- stage `openai-codex-app-server-sdk` once with an exact `openai-codex-cli-bin==...` dependency
+- stage `openai-codex` once with an exact `openai-codex-cli-bin==...` dependency
 - stage `openai-codex-cli-bin` on each supported platform runner with the same pinned runtime version
 - build and publish `openai-codex-cli-bin` as platform wheels only through PyPI trusted publishing; do not publish an sdist
 
 ## Compatibility and versioning
 
-- Package: `openai-codex-app-server-sdk`
+- Package: `openai-codex`
 - Runtime package: `openai-codex-cli-bin`
 - Python: `>=3.10`
 - Target protocol: Codex `app-server` JSON-RPC v2