fix: make lazy facade entry reclassification effective under rolldown-vite

normalizeEmittedLazyEntries used `delete entry.isEntry` to reclassify
emitted lazy facade chunks as dynamic entries. Under rolldown-vite
(Vite 8) the bundle passed to generateBundle materializes chunks as
proxies over native data: property assignment is trapped and synced
back to the native bundle after the hook, but a delete falls through
to the throwaway JS target while the proxy's read cache keeps serving
the previously read value. The reclassification therefore silently
no-oped and downstream plugins still saw every facade chunk flagged
isEntry, e.g. TanStack Start failing client builds with "multiple
entries detected".

Assign `isEntry = false` instead, which behaves identically on plain
objects (Rollup bundles and the parsed Vite manifest.json).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: brenelz

.changeset/lazy-entry-rolldown-reclassify.md

@@ -0,0 +1,5 @@
+---
+'vite-plugin-solid': patch
+---
+
+Reclassify emitted lazy facade chunks by assigning `isEntry = false` instead of deleting the property. Under rolldown-vite (Vite 8), bundle chunks in `generateBundle` are proxies whose set trap syncs assignments back to the native bundle, while a delete is swallowed by the proxy's read cache — so the reclassification silently no-oped and downstream plugins (e.g. TanStack Start's manifest plugin) still saw every lazy facade chunk as an application entry, failing builds with "multiple entries detected".

src/index.ts

@@ -268,7 +268,11 @@ function normalizeEmittedLazyEntries(manifest: Record<string, any>) {
   for (const key of dynamicKeys) {
     const entry = manifest[key];
     if (entry && entry.isEntry) {
-      delete entry.isEntry;
+      // Assign rather than delete: rolldown-vite materializes bundle chunks
+      // as proxies whose set trap syncs changes back to the native bundle,
+      // while a delete is swallowed by the proxy's read cache and never
+      // reaches it (or downstream plugins).
+      entry.isEntry = false;
       entry.isDynamicEntry = true;
     }
   }