sdk: launch packaged Codex runtimes

## Why

The Python and TypeScript SDKs launch the native Codex runtime directly, so they need to understand the same package layout that the release artifacts now use. Without this, SDK runtime wheels would keep carrying only a loose `bin/codex` plus ad hoc helper binaries, the TypeScript SDK would keep resolving the legacy optional-dependency layout, and bundled `codex-path` tools such as `rg` would not be prepended when the SDK starts Codex.

## What Changed

- Stage `openai-codex-cli-bin` from a Codex package directory, including `codex-package.json`, `bin/`, `codex-resources/`, and `codex-path/`.
- Preserve the legacy loose-binary staging path for compatibility, but shape its output like a package directory and put helper resources under `codex-resources/`.
- Expose Python runtime helpers for the bundled package directory and `codex-path`, and prepend that path when `openai_codex` launches the installed runtime.
- Teach the TypeScript SDK to resolve package-layout optional dependencies while keeping the legacy layout fallback.
- Update the Rust release workflows to build Python runtime wheels from the generated Codex package directories instead of loose binaries.

## Test Plan

- `python3 -m py_compile sdk/python/scripts/update_sdk_artifacts.py sdk/python/src/openai_codex/client.py sdk/python-runtime/src/codex_cli_bin/__init__.py`
- `uv run --frozen --project sdk/python --extra dev ruff check sdk/python/scripts/update_sdk_artifacts.py sdk/python/src/openai_codex/client.py sdk/python/tests/test_artifact_workflow_and_binaries.py sdk/python-runtime/src/codex_cli_bin/__init__.py`
- `uv run --frozen --project sdk/python --extra dev pytest sdk/python/tests/test_artifact_workflow_and_binaries.py`
- `pnpm eslint src/exec.ts tests/exec.test.ts`
- `pnpm test --runInBand tests/exec.test.ts`

.github/workflows/rust-release-windows.yml

@@ -258,16 +258,12 @@ jobs:
 
           stage_dir="${RUNNER_TEMP}/openai-codex-cli-bin-${{ matrix.target }}"
           wheel_dir="${GITHUB_WORKSPACE}/python-runtime-dist/${{ matrix.target }}"
-          # Keep the helpers next to codex.exe in the runtime wheel so Windows
-          # sandbox/elevation lookup matches the standalone release zip.
           python "${GITHUB_WORKSPACE}/sdk/python/scripts/update_sdk_artifacts.py" \
             stage-runtime \
             "$stage_dir" \
-            "${GITHUB_WORKSPACE}/codex-rs/target/${{ matrix.target }}/release/codex.exe" \
+            "${RUNNER_TEMP}/codex-package-${{ matrix.target }}" \
             --codex-version "${GITHUB_REF_NAME}" \
-            --platform-tag "$platform_tag" \
-            --resource-binary "${GITHUB_WORKSPACE}/codex-rs/target/${{ matrix.target }}/release/codex-command-runner.exe" \
-            --resource-binary "${GITHUB_WORKSPACE}/codex-rs/target/${{ matrix.target }}/release/codex-windows-sandbox-setup.exe"
+            --platform-tag "$platform_tag"
           "${RUNNER_TEMP}/python-runtime-build-venv/Scripts/python.exe" -m build --wheel --outdir "$wheel_dir" "$stage_dir"
 
       - name: Upload Python runtime wheel

.github/workflows/rust-release.yml

@@ -569,18 +569,10 @@ jobs:
             "${GITHUB_WORKSPACE}/sdk/python/scripts/update_sdk_artifacts.py"
             stage-runtime
             "$stage_dir"
-            "${GITHUB_WORKSPACE}/codex-rs/target/${{ matrix.target }}/release/codex"
+            "${RUNNER_TEMP}/codex-package-${{ matrix.target }}"
             --codex-version "${GITHUB_REF_NAME}"
             --platform-tag "$platform_tag"
           )
-          if [[ "${{ matrix.target }}" == *linux* ]]; then
-            # Keep bwrap in the runtime wheel so Linux sandbox fallback behavior
-            # matches the standalone release bundle on hosts without system bwrap.
-            stage_runtime_args+=(
-              --resource-binary
-              "${GITHUB_WORKSPACE}/codex-rs/target/${{ matrix.target }}/release/bwrap"
-            )
-          fi
           python3 "${stage_runtime_args[@]}"
           "${RUNNER_TEMP}/python-runtime-build-venv/bin/python" -m build --wheel --outdir "$wheel_dir" "$stage_dir"
 
@@ -800,6 +792,20 @@ jobs:
             cp "$dmg_source" "$dest/$dmg_name"
           fi
 
+      - name: Build Codex package archive
+        shell: bash
+        env:
+          TARGET: ${{ matrix.target }}
+          BUNDLE: ${{ matrix.bundle }}
+        run: |
+          set -euo pipefail
+          bash "${GITHUB_WORKSPACE}/.github/scripts/build-codex-package-archive.sh" \
+            --target "$TARGET" \
+            --bundle "$BUNDLE" \
+            --entrypoint-dir "dist/${TARGET}" \
+            --archive-dir "dist/${TARGET}" \
+            --target-suffixed-entrypoint
+
       - name: Build Python runtime wheel
         if: ${{ matrix.bundle == 'primary' }}
         shell: bash
@@ -828,25 +834,11 @@ jobs:
             "${GITHUB_WORKSPACE}/sdk/python/scripts/update_sdk_artifacts.py" \
             stage-runtime \
             "$stage_dir" \
-            "${GITHUB_WORKSPACE}/codex-rs/dist/${{ matrix.target }}/codex-${{ matrix.target }}" \
+            "${RUNNER_TEMP}/codex-package-${{ matrix.target }}" \
             --codex-version "${GITHUB_REF_NAME}" \
             --platform-tag "$platform_tag"
           "${RUNNER_TEMP}/python-runtime-build-venv/bin/python" -m build --wheel --outdir "$wheel_dir" "$stage_dir"
 
-      - name: Build Codex package archive
-        shell: bash
-        env:
-          TARGET: ${{ matrix.target }}
-          BUNDLE: ${{ matrix.bundle }}
-        run: |
-          set -euo pipefail
-          bash "${GITHUB_WORKSPACE}/.github/scripts/build-codex-package-archive.sh" \
-            --target "$TARGET" \
-            --bundle "$BUNDLE" \
-            --entrypoint-dir "dist/${TARGET}" \
-            --archive-dir "dist/${TARGET}" \
-            --target-suffixed-entrypoint
-
       - name: Upload Python runtime wheel
         if: ${{ matrix.bundle == 'primary' }}
         uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0