fix(ui): stub Node built-ins for fixture bundle

Replace platform: 'node' (incompatible with iife browser bundle) with
explicit aliases for node:async_hooks, node:crypto, node:fs/promises,
node:path pointing at e2e/ui/node-stubs.mjs. Provides shape-compatible
exports so esbuild can bundle the UI fixture without failing on Node
built-ins. Increase webServer timeout to 120s for reliable startup.

e2e/ui/fixture-server.mjs

@@ -23,6 +23,7 @@ const actions = new Set([
 	"@/actions/article-recovery",
 	"@/actions/admin-media",
 ]);
+const nodeStubs = path.join(root, "e2e/ui/node-stubs.mjs");
 const bundle = await build({
 	entryPoints: [path.join(fixtures, "entry.tsx")],
 	bundle: true,
@@ -30,8 +31,13 @@ const bundle = await build({
 	outdir: path.join(root, "test-results/ui-fixture"),
 	format: "iife",
 	jsx: "automatic",
-	platform: "node",
-	alias: { "@": path.join(root, "src") },
+	alias: {
+		"@": path.join(root, "src"),
+		"node:async_hooks": nodeStubs,
+		"node:crypto": nodeStubs,
+		"node:fs/promises": nodeStubs,
+		"node:path": nodeStubs,
+	},
 	define: { "process.env.NODE_ENV": '"production"' },
 	plugins: [
 		{