Push HMR updates before the SSR rebuild in dev

Client-only edits are sent to the browser right after the hydration build,
without re-running server functions; SSR rebuilds afterwards and props are
re-fetched only when a .server.ts output changed or after fullRebuild. Page
requests wait for an in-flight SSR rebuild. The SSR build no longer runs
Tailwind, the PostCSS processor is reused across rebuilds, and the watcher
debounce drops from 200ms to 50ms.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

dist/functions/server/web-pages/handle-web-pages.js

@@ -5,6 +5,7 @@ import getCache from "../../cache/get-cache";
 import generateWebPageResponseFromComponentReturn from "./generate-web-page-response-from-component-return";
 import grabPageComponent from "./grab-page-component";
 import grabPageErrorComponent from "./grab-page-error-component";
+import { awaitSSRRebuild } from "../../bundler/pages-ssr-context-bundler";
 export default async function handleWebPages({ req, }) {
     try {
         const is_dev = isDevelopment();
@@ -31,6 +32,11 @@ export default async function handleWebPages({ req, }) {
             }
             catch (error) { }
         }
+        // HMR pushes client updates before the SSR rebuild finishes; a page
+        // load in that window waits so SSR HTML matches the new bundle.
+        if (is_dev) {
+            await awaitSSRRebuild();
+        }
         const componentRes = await grabPageComponent({
             req,
         });