feat: complete MVP foundation auth and dashboard

tests/route-guards.test.ts

@@ -0,0 +1,18 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { getDashboardRedirectPath } from "../lib/route-guards";
+
+test("getDashboardRedirectPath sends guests back to the auth entry", () => {
+  assert.equal(getDashboardRedirectPath(null), "/");
+});
+
+test("getDashboardRedirectPath lets authenticated mock users stay on dashboard", () => {
+  assert.equal(
+    getDashboardRedirectPath({
+      name: "Matthias Meister",
+      email: "matthias@webdev-pipeline.local",
+    }),
+    null,
+  );
+});