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/bundler/pages-ssr-context-bundler.js

@@ -2,7 +2,7 @@ import * as esbuild from "esbuild";
 import grabAllPages from "../../utils/grab-all-pages";
 import grabDirNames from "../../utils/grab-dir-names";
 import isDevelopment from "../../utils/is-development";
-import tailwindEsbuildPlugin from "../server/web-pages/tailwind-esbuild-plugin";
+import { cssStubEsbuildPlugin } from "../server/web-pages/tailwind-esbuild-plugin";
 import grabPageReactComponentString from "../server/web-pages/grab-page-react-component-string";
 import grabRootFilePath from "../server/web-pages/grab-root-file-path";
 import ssrVirtualFilesPlugin from "./plugins/ssr-virtual-files-plugin";
@@ -87,6 +87,16 @@ export default async function enqueueSSRRebuild(params) {
     rebuild_in_flight = run;
     return run;
 }
+/**
+ * Resolves once the in-flight SSR rebuild (if any) has finished. Lets page
+ * requests avoid rendering stale SSR modules against a newer client bundle.
+ */
+export async function awaitSSRRebuild() {
+    try {
+        await rebuild_in_flight;
+    }
+    catch (error) { }
+}
 async function doSSRRebuild(params) {
     const force = Boolean(params?.force);
     const dev = isDevelopment();
@@ -137,7 +147,9 @@ async function doSSRRebuild(params) {
                 entryNames: "[dir]/[hash]",
                 metafile: true,
                 plugins: [
-                    tailwindEsbuildPlugin,
+                    // SSR CSS output is never served (HTML links the
+                    // hydration build's CSS), so skip Tailwind here.
+                    cssStubEsbuildPlugin,
                     ssrVirtualFilesPlugin({
                         getEntryToPage: () => current_entry_map,
                     }),