fix(web): withPayload + redirect admin + externalized packages

Final working pattern: withPayload via require() for build
compatibility, admin page replaced with redirect (no RootPage
import = no React #130), payload packages externalized from
turbopack bundle. Blog/changelog use server-side getPayload().

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/next.config.ts

@@ -1,5 +1,8 @@
 import type { NextConfig } from "next";
 
+// eslint-disable-next-line @typescript-eslint/no-require-imports
+const { withPayload } = require("@payloadcms/next/withPayload");
+
 import env from "./env.config";
 
 const INTERNAL_PACKAGES = [
@@ -121,4 +124,4 @@ const withBundleAnalyzer = require("@next/bundle-analyzer")({
   enabled: env.ANALYZE,
 });
 
-export default withBundleAnalyzer(config);
+export default withPayload(withBundleAnalyzer(config));