v4.0.8

Tracks the extension 4.0.8 suite (the versioning convention: this package's
version follows the CLI suite release it pairs with). One tool was added since
3.17.0, extension_release_promote, bringing the surface to 27 tools.

• Bump extension-create, extension-develop, extension-install from
  ^3.13.5 to ^4.0.8. All consumed APIs (extensionCreate, extensionBuild,
  extensionInstall, getManagedBrowsersCacheRoot) and all CLI verbs the
  tools shell out to (dev, start, preview, logs, eval, storage,
  reload, open, inspect, publish, including --allow-control,
  --allow-eval and --no-browser) are unchanged in 4.x; verified
  end-to-end (create -> build -> dev ready contract -> manifest validate).
• package.json version now matches the published line (was a stale 0.0.1)
  and the server reports its version from package.json instead of a
  hardcoded string (previously stuck at 3.13.5).
• browser-extension-manifest-fields ^2.2.8 -> ^2.2.9.
• vitest config: resolve the extension-* test aliases from the packages'
  exports maps; 4.x dropped the CJS entry, so require.resolve on the bare
  specifier no longer works.