test: cover captcha env fallback, cache TTLs and public e2e flows

- unit: captcha env fallback/precedence (DB wins, explicit "none") and
  perf-ttls defaults, overrides and invalid values
- e2e: public page render + image health, register form and Turnstile
  widget consistency, anonymous auth-guard redirects, plus warm latency
  budgets and cache-control contracts

e2e/helpers.ts

@@ -0,0 +1,62 @@
+import { expect, type Page } from "@playwright/test";
+
+/**
+ * Shared assertions for the read-only public e2e suite. These specs run against
+ * a live CMS (see `playwright.config.ts`) and must never mutate data — they
+ * guard the "everything loads, nothing is broken" contract that no unit test
+ * can see.
+ */
+
+/** Fails if Next rendered a runtime/server error boundary into the page. */
+export async function expectNoApplicationError(page: Page) {
+	await expect(page.locator("body")).not.toContainText("Application error");
+	await expect(page.locator("body")).not.toContainText("Internal Server Error");
+}
+
+/**
+ * Every <img> that finished loading must have decoded pixels. A failed request
+ * (404, broken CMS media, bad avatar figure) reports `complete === true` with
+ * `naturalWidth === 0`, which is what this catches. Intentionally lazy images
+ * that are still pending (`complete === false`) are ignored.
+ */
+export async function expectNoBrokenImages(page: Page) {
+	const broken = await page.evaluate(() => {
+		return Array.from(document.images)
+			.filter((img) => {
+				const src = img.currentSrc || img.src;
+				if (!src || src.startsWith("data:")) return false;
+				return img.complete && img.naturalWidth === 0;
+			})
+			.map((img) => img.currentSrc || img.src);
+	});
+	expect(broken, `broken images:\n${broken.join("\n")}`).toEqual([]);
+}
+
+/** No horizontal scrollbar — the classic mobile layout regression. */
+export async function expectNoHorizontalOverflow(page: Page) {
+	const overflowing = await page.evaluate(() => {
+		const doc = document.documentElement;
+		return doc.scrollWidth > window.innerWidth + 1;
+	});
+	expect(overflowing, "page scrolls horizontally").toBe(false);
+}
+
+/**
+ * Walks the page top-to-bottom so `loading="lazy"` images below the fold get a
+ * chance to start before the broken-image check runs.
+ */
+export async function scrollThroughPage(page: Page) {
+	await page.evaluate(async () => {
+		const step = window.innerHeight;
+		for (let y = 0; y < document.body.scrollHeight; y += step) {
+			window.scrollTo(0, y);
+			await new Promise((resolve) => setTimeout(resolve, 80));
+		}
+		window.scrollTo(0, 0);
+	});
+}
+
+/** Skips a spec when the CMS answered with a maintenance redirect. */
+export function isMaintenanceRedirect(url: string) {
+	return /\/maintenance(?:$|[/?])/.test(url);
+}