feat: enable edge runtime for Docker environments

Extends the server.edge runtime configuration to include Docker environments in addition to Cloudflare Pages.
This change allows React 19 to run properly in Docker by using the edge-compatible server runtime,
avoiding the need for MessageChannel polyfills.

Author: miantiao-me

astro.config.mjs

@@ -34,9 +34,11 @@ export default defineConfig({
     resolve: {
       // Use react-dom/server.edge instead of react-dom/server.browser for React 19.
       // Without this, MessageChannel from node:worker_threads needs to be polyfilled.
-      alias: import.meta.env.PROD && adapterProvider === 'cloudflare_pages' && {
-        'react-dom/server': 'react-dom/server.edge',
-      },
+      alias: import.meta.env.PROD
+        && (adapterProvider === 'cloudflare_pages' || process.env.DOCKER)
+        && {
+          'react-dom/server': 'react-dom/server.edge',
+        },
     },
   },
 })