Isolate anonymous auth page from Blazor

tests/e2e/smoke.spec.js

@@ -32,6 +32,18 @@ test("home page loads auth entry points", async ({ page }) => {
   await expect(page.getByLabel("Password").nth(1)).toBeVisible();
 });
 
+test("home document renders static auth markup without bootstrapping blazor", async ({ request }) => {
+  const response = await request.get("/");
+  expect(response.ok()).toBeTruthy();
+
+  const html = await response.text();
+  expect(html).not.toContain("Connecting...");
+  expect(html).toContain("Register or log in to join a campaign session.");
+  expect(html).not.toContain("_framework/blazor.web.js");
+  expect(html).not.toContain("<!--Blazor:");
+  expect(html).toContain("data-auth-page");
+});
+
 test("successful login transitions to play workspace", async ({ page, context }) => {
   const username = `login-${Date.now()}`;
   const password = "Password123";