feat(app): locale migration L3b — retire internal-marketing pilot

AGENTS.md

@@ -26,7 +26,7 @@ Cursor rules to apply (see each file for full wording):
 
 ### Instant Navigations (Next.js 16.3) — not on Pages Router yet
 
-dStruct is **mostly Pages Router** (`src/pages/`). An **App Router pilot** lives under `src/app/internal-marketing/[locale]/` (home, privacy, daily; noindex). **Instant Navigations** (`cacheComponents`, `partialPrefetching`, `'use cache'`, `unstable_instant`, Instant Insights) requires broader App Router migration. Do not enable `cacheComponents` or add `'use cache'` under `src/pages/`.
+dStruct public marketing and app routes live on **App Router** (`src/app/(default-locale)/`, `src/app/[lang]/`). Legacy `/internal-marketing/*` and `/en/*` URLs **308 redirect** to public routes (L3b). **Instant Navigations** (`cacheComponents`, `partialPrefetching`, `'use cache'`, `unstable_instant`, Instant Insights) requires resolving root `headers()` blockers. Do not enable `cacheComponents` or add `'use cache'` under `src/pages/`.
 
 Before implementing Instant Navigations, read:
 

e2e/app-locale-routes.spec.ts

@@ -3,26 +3,26 @@ import { expect, test } from "@playwright/test";
 /**
  * Smoke tests for public `app/[lang]/*` routes (locale migration L1).
  *
- * Explicit `/en/*` URLs redirect to unprefixed canonicals in L2; see
- * `e2e/locale-migration-l2.spec.ts` for unprefixed `/` and `/privacy`.
+ * Default locale (`en`) is served from `(default-locale)/` at unprefixed URLs;
+ * see `e2e/locale-migration-l2.spec.ts` and `e2e/locale-migration-l3b.spec.ts`.
  */
-test.describe("app/[lang] public routes", () => {
-  test("en home is indexable with public canonical", async ({ page }) => {
-    await page.goto("/en");
+test.describe("app/[lang] public routes (non-default locales)", () => {
+  test("de home is indexable with locale canonical", async ({ page }) => {
+    await page.goto("/de");
     await expect(page).toHaveTitle(/dStruct/);
     await expect(page.locator('meta[name="robots"]')).toHaveCount(0);
     await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
       "href",
-      "https://dstruct.pro/",
+      "https://dstruct.pro/de",
     );
   });
 
-  test("en privacy is indexable with public canonical", async ({ page }) => {
-    await page.goto("/en/privacy");
+  test("de privacy is indexable with locale canonical", async ({ page }) => {
+    await page.goto("/de/privacy");
     await expect(page.locator('meta[name="robots"]')).toHaveCount(0);
     await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
       "href",
-      "https://dstruct.pro/privacy",
+      "https://dstruct.pro/de/privacy",
     );
   });
 
@@ -35,29 +35,29 @@ test.describe("app/[lang] public routes", () => {
     );
   });
 
-  test("en playground landing is indexable with public canonical", async ({
+  test("de playground landing is indexable with locale canonical", async ({
     page,
   }) => {
-    await page.goto("/en/playground");
+    await page.goto("/de/playground");
     await expect(page).toHaveTitle(/Playground/i);
     await expect(page.locator('meta[name="robots"]')).toHaveCount(0);
     await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
       "href",
-      "https://dstruct.pro/playground",
+      "https://dstruct.pro/de/playground",
     );
   });
 
-  test("en profile is noindex with public canonical", async ({ page }) => {
+  test("de profile is noindex with locale canonical", async ({ page }) => {
     const userId = "e2e-app-lang-user";
-    await page.goto(`/en/profile/${userId}`);
-    await expect(page).toHaveTitle(/Profile/i);
+    await page.goto(`/de/profile/${userId}`);
+    await expect(page).toHaveTitle(/Profil|Profile/i);
     await expect(page.locator('meta[name="robots"]')).toHaveAttribute(
       "content",
       /noindex/i,
     );
     await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
       "href",
-      `https://dstruct.pro/profile/${userId}`,
+      `https://dstruct.pro/de/profile/${userId}`,
     );
   });
 });

e2e/locale-migration-l3b.spec.ts

@@ -0,0 +1,71 @@
+import { expect, test } from "@playwright/test";
+
+/**
+ * L3b: legacy `/internal-marketing/*` and duplicate `/en/*` URLs 308 to public App routes.
+ */
+test.describe("locale migration L3b legacy redirects", () => {
+  test("legacy URLs respond with 308 permanent redirect", async ({
+    request,
+  }) => {
+    const response = await request.get("/internal-marketing/en/privacy", {
+      maxRedirects: 0,
+    });
+    expect(response.status()).toBe(308);
+    expect(response.headers().location).toBe("/privacy");
+  });
+
+  test("internal-marketing en home redirects to /", async ({ page }) => {
+    const response = await page.goto("/internal-marketing/en");
+    expect(response?.status()).toBeLessThan(400);
+    await expect(page).toHaveURL(/\/$/);
+    await expect(page).toHaveTitle(/dStruct/);
+  });
+
+  test("internal-marketing en privacy redirects to /privacy", async ({
+    page,
+  }) => {
+    await page.goto("/internal-marketing/en/privacy");
+    await expect(page).toHaveURL(/\/privacy$/);
+    await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
+      "href",
+      "https://dstruct.pro/privacy",
+    );
+  });
+
+  test("internal-marketing de daily redirects to /de/daily", async ({
+    page,
+  }) => {
+    await page.goto("/internal-marketing/de/daily");
+    await expect(page).toHaveURL(/\/de\/daily$/);
+    await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
+      "href",
+      "https://dstruct.pro/de/daily",
+    );
+  });
+
+  test("internal-marketing en playground redirects to /playground", async ({
+    page,
+  }) => {
+    await page.goto("/internal-marketing/en/playground");
+    await expect(page).toHaveURL(/\/playground$/);
+    await expect(page).toHaveTitle(/Playground/i);
+  });
+
+  test("internal-marketing en profile redirects to /profile/:userId", async ({
+    page,
+  }) => {
+    const userId = "e2e-test-user";
+    await page.goto(`/internal-marketing/en/profile/${userId}`);
+    await expect(page).toHaveURL(new RegExp(`/profile/${userId}$`));
+    await expect(page).toHaveTitle(/Profile/i);
+  });
+
+  test("/en/privacy redirects to unprefixed /privacy", async ({ page }) => {
+    await page.goto("/en/privacy");
+    await expect(page).toHaveURL(/\/privacy$/);
+    await expect(page.locator('link[rel="canonical"]')).toHaveAttribute(
+      "href",
+      "https://dstruct.pro/privacy",
+    );
+  });
+});

next.config.mjs

@@ -85,6 +85,42 @@ const config = {
   sassOptions: {
     silenceDeprecations: ["legacy-js-api"],
   },
+  async redirects() {
+    return [
+      // L3b: retire `/internal-marketing/*` App pilot → public App routes (308).
+      {
+        source: "/internal-marketing/en",
+        destination: "/",
+        permanent: true,
+      },
+      {
+        source: "/internal-marketing/en/:path*",
+        destination: "/:path*",
+        permanent: true,
+      },
+      {
+        source: "/internal-marketing/:locale",
+        destination: "/:locale",
+        permanent: true,
+      },
+      {
+        source: "/internal-marketing/:locale/:path*",
+        destination: "/:locale/:path*",
+        permanent: true,
+      },
+      // SEO: dedupe default-locale `/en/*` vs unprefixed URLs.
+      {
+        source: "/en",
+        destination: "/",
+        permanent: true,
+      },
+      {
+        source: "/en/:path*",
+        destination: "/:path*",
+        permanent: true,
+      },
+    ];
+  },
   turbopack: {
     rules: {
       "*.txt": {