Ship the standalone executor in release packages (#57837)

## What changed

- Include `codex-exec-server` in canonical CLI and app-server packages and advertise its path through `execServer` in `codex-package.json`.
- Build and sign the executor in release workflows, preserve signed prebuilt inputs, and verify packaged signatures. Use empty entitlements for the macOS executor.
- Have installers check for the executor when package metadata advertises it, while continuing to accept older packages.
- Omit the standalone executor and its manifest entry from npm packages to stay within npm's package size limit. Keep `codex exec-server` and its runtime helpers available.

## Testing

Add package smoke tests for executor initialization, version reporting, filesystem and process sandbox enforcement, and invalid-argument/configuration parity with `codex exec-server`. Extend archive, npm staging, and macOS signing tests to cover executor contents, executable permissions, preserved bytes, and entitlement verification.

GitOrigin-RevId: bc741fe7faa6fe631d076de18d448c55247c23c7

codex-cli/scripts/README.md

@@ -18,6 +18,12 @@ When `--package codex` is provided, the staging helper builds the lightweight
 `@openai/codex` meta package plus all platform-native `@openai/codex` variants
 that are later published under platform-specific dist-tags.
 
+The npm variants omit the standalone `codex-exec-server` executable and its
+`execServer` manifest entry to keep uploads within npm's package size limit.
+They retain `codex exec-server` through the CLI, the code-mode host, and the
+platform sandbox helpers. Canonical release archives retain the standalone
+executor; npm staging changes only the package copy.
+
 Direct `build_npm_package.py` invocations are still useful for package-specific
 debugging, but native packages expect `--vendor-src` to point at a prehydrated
 `vendor/` tree. Release packaging should use `scripts/stage_npm_packages.py`

codex-cli/scripts/build_npm_package.py

@@ -391,6 +391,16 @@ def copy_native_binaries(
             if dest_target_dir.exists():
                 shutil.rmtree(dest_target_dir)
             shutil.copytree(target_dir, dest_target_dir)
+            # standalone exec-server is a binary that is equal to codex exec-server, do not publish it to npm
+            for name in ("codex-exec-server", "codex-exec-server.exe"):
+                (dest_target_dir / "bin" / name).unlink(missing_ok=True)
+            metadata_path = dest_target_dir / "codex-package.json"
+            if metadata_path.is_file():
+                metadata = json.loads(metadata_path.read_text(encoding="utf-8"))
+                metadata.pop("execServer", None)
+                metadata_path.write_text(
+                    json.dumps(metadata, indent=2) + "\n", encoding="utf-8"
+                )
         else:
             dest_target_dir.mkdir(parents=True, exist_ok=True)