defineConfig drops own properties of Promise plugins (breaks Vike discovery) #3152

What

withoutVitePlusTestPlugins maps plugin instanceof Promise to plugin.then(withoutVitePlusTestPlugins). .then() creates a new promise that does not carry the original promise's own properties.

Impact

vike() (vike/plugin@0.4.268) returns a Promise carrying _vikeVitePluginOptions as an own property — verified present on the promise itself and absent from all 41 resolved plugins. Vike discovers its plugin by scanning the raw user config for that field, so after vp's re-wrap the field is gone: vike build warns Omitting Vike's Vite plugin and then fails inside @brillout/vite-plugin-server-entry (resolveConfig).

Current workaround is a sync marker object that copies the field (awaiting first is not an option — it destroys the marker; a lazy async factory reintroduces the same failure since it yields [Promise]).

Ask

Preserve own props across the re-wrap (e.g. copy them onto the settled wrapper), or document that Promise plugins must be prop-free so downstream authors know to use a marker.

Repro

// vite.config.ts (loaded through vp's defineConfig)
import { defineConfig } from 'vite-plus';
import vike from 'vike/plugin';
export default defineConfig({ plugins: [vike()] });

vike build fails as above. The identical config through vite's own defineConfig builds fine.

Versions

vite-plus 1.3.0, vike 0.4.268, vite-plus-core 1.3.0