improvement: generate default oauth2RedirectUrl based on page location (via #5085)

test/e2e-cypress/tests/features/dynamic-default-oauth.js

@@ -0,0 +1,10 @@
+describe("dynamic default oauth2RedirectUrl", () => {
+  it("should render the OAS3 badge correctly", () => {
+    // This is a sanity check to make sure the badge is present.
+    // If this is failing, it's probably not related to #4865.
+    cy.visit("/")
+      .window()
+      .then(win => win.ui.getConfigs())
+      .should("include", { oauth2RedirectUrl: "http://localhost:3230/oauth2-redirect.html" })
+  })
+})