fix(pages): pass through any Response returned from page loaders

packages/react/src/plugin-pages.ts

@@ -139,12 +139,9 @@ ${generateComponentManifest(scan, pagesDir)}
 const PREAMBLE_SCRIPT = ${JSON.stringify(preambleScript)};
 
 function serializePageData(pageObj) {
-  return JSON.stringify(pageObj)
-    .replaceAll("<", "\\u003c")
-    .replaceAll(">", "\\u003e")
-    .replaceAll("&", "\\u0026")
-    .replaceAll("\u2028", "\\u2028")
-    .replaceAll("\u2029", "\\u2029");
+  return JSON.stringify(pageObj).replace(/[<>&\\u2028\\u2029]/g, function(c) {
+    return String.fromCharCode(92) + "u" + c.charCodeAt(0).toString(16).padStart(4, "0");
+  });
 }
 
 export async function renderPage(pageObj, assetTags) {

packages/void/src/pages/protocol.ts

@@ -1,6 +1,7 @@
 import { ValidationError } from "./validation-error";
 import { DEFERRED, separateDeferred, type ResolvedDeferredGroup } from "./defer";
 import { resolveHead, type HeadDescriptor, type HeadConfig } from "./head";
+import { isConvertedResponse } from "../runtime/response";
 
 export { ValidationError };
 
@@ -127,9 +128,17 @@ export async function handlePageGet(
   let props: Record<string, unknown> = {};
   if (handler) {
     const result = await handler(c);
-    if (result instanceof Response) {
-      const status = result.status;
-      if (status >= 300) return result;
+    // Responses from convertReturnValue (withValidator/middleware paths) always
+    // flow through to extractProps — they wrap plain return values (objects as
+    // 200 JSON, null/undefined as 204, strings as text/html) and must be
+    // unwrapped as page props.
+    //
+    // User-returned Responses: pass through errors/redirects (>= 300) and
+    // non-JSON 200s (file downloads, streams). JSON 200s are still extracted
+    // as props for backward compat with loaders using c.json().
+    if (result instanceof Response && !isConvertedResponse(result)) {
+      const ct = result.headers.get("content-type") || "";
+      if (result.status >= 300 || !ct.includes("application/json")) return result;
     }
     props = await extractProps(result);
   }

packages/void/src/runtime/response.ts

@@ -1,3 +1,15 @@
+/**
+ * Tracks responses created by convertReturnValue (as opposed to responses
+ * explicitly constructed by user code). Used by handlePageGet to decide
+ * whether a Response should be passed through or unwrapped as page props.
+ */
+const convertedResponses = new WeakSet<Response>();
+
+/** Returns true if the value is a Response that was created by convertReturnValue. */
+export function isConvertedResponse(value: unknown): boolean {
+  return value instanceof Response && convertedResponses.has(value);
+}
+
 /**
  * Convert a handler's return value to a Web Response.
  *
@@ -11,16 +23,17 @@ export function convertReturnValue(value: unknown): Response {
     return value;
   }
 
+  let response: Response;
   if (value === null || value === undefined) {
-    return new Response(null, { status: 204 });
-  }
-
-  if (typeof value === "string") {
-    return new Response(value, {
+    response = new Response(null, { status: 204 });
+  } else if (typeof value === "string") {
+    response = new Response(value, {
       headers: { "Content-Type": "text/html; charset=utf-8" },
     });
+  } else {
+    // object, array, number, boolean → JSON
+    response = Response.json(value);
   }
-
-  // object, array, number, boolean → JSON
-  return Response.json(value);
+  convertedResponses.add(response);
+  return response;
 }