test(web-next): e2e cross-feature sign-up→welcome-email flow

End-to-end proof-of-life. bindAllDevSeed wires InMemoryEventBus +
InMemoryJobQueue across all features. signUpController publishes
auth.user.signed-up; marketing-pages' handler enqueues
marketing-pages.send-welcome-email; the in-memory queue dispatches
the wrapped job which records on RecordingMailerService.

Adds ./di/container, ./di/symbols, ./services/mailer, and
./services/recording-mailer to auth + marketing-pages exports so
the e2e test can resolve from the per-feature containers without
deep-importing.

apps/web-next/src/__tests__/sign-up-welcome-email.test.ts

@@ -0,0 +1,44 @@
+// Cross-feature proof-of-life: signing up in @repo/auth publishes
+// userSignedUpEvent on the shared bus, marketing-pages' subscriber enqueues
+// a send-welcome-email job on the shared queue, and dev-seed's
+// InMemoryJobQueue.register() dispatches it to the wrapped job — which
+// records the call on the bound RecordingMailerService.
+
+import "reflect-metadata";
+import { describe, it, expect, beforeEach } from "vitest";
+import { bindAllDevSeed, __resetBindStateForTests } from "@/server/bind-production";
+import { authContainer } from "@repo/auth/di/container";
+import { AUTH_SYMBOLS } from "@repo/auth/di/symbols";
+import type { ISignUpController } from "@repo/auth";
+import { marketingPagesContainer } from "@repo/marketing-pages/di/container";
+import { MARKETING_PAGES_SYMBOLS } from "@repo/marketing-pages/di/symbols";
+import { RecordingMailerService } from "@repo/marketing-pages/services/recording-mailer";
+
+describe("e2e: sign-up triggers welcome email via cross-feature event", () => {
+  beforeEach(() => {
+    __resetBindStateForTests();
+  });
+
+  it("delivers a welcome email after a successful sign-up", async () => {
+    await bindAllDevSeed();
+
+    const mailer = marketingPagesContainer.get<RecordingMailerService>(
+      MARKETING_PAGES_SYMBOLS.IMailerService,
+    );
+    const signUp = authContainer.get<ISignUpController>(AUTH_SYMBOLS.ISignUpController);
+
+    await signUp({
+      username: "testuser",
+      password: "secret_password",
+      confirmPassword: "secret_password",
+    });
+
+    // The InMemoryJobQueue dispatches the registered handler on setImmediate;
+    // wait for microtasks + one setImmediate tick to settle.
+    await new Promise((r) => setImmediate(r));
+
+    expect(mailer.sent).toEqual([
+      { userId: expect.any(String), email: "testuser@example.local" },
+    ]);
+  });
+});

packages/auth/package.json

@@ -9,7 +9,9 @@
     "./cms": "./src/integrations/cms/index.ts",
     "./api": "./src/integrations/api/router.ts",
     "./di/bind-production": "./src/di/bind-production.ts",
-    "./di/bind-dev-seed": "./src/di/bind-dev-seed.ts"
+    "./di/bind-dev-seed": "./src/di/bind-dev-seed.ts",
+    "./di/container": "./src/di/container.ts",
+    "./di/symbols": "./src/di/symbols.ts"
   },
   "scripts": {
     "build": "tsc --noEmit",

packages/marketing-pages/package.json

@@ -9,7 +9,11 @@
     "./cms": "./src/integrations/cms/index.ts",
     "./api": "./src/integrations/api/router.ts",
     "./di/bind-production": "./src/di/bind-production.ts",
-    "./di/bind-dev-seed": "./src/di/bind-dev-seed.ts"
+    "./di/bind-dev-seed": "./src/di/bind-dev-seed.ts",
+    "./di/container": "./src/di/container.ts",
+    "./di/symbols": "./src/di/symbols.ts",
+    "./services/mailer": "./src/application/services/mailer.service.interface.ts",
+    "./services/recording-mailer": "./src/infrastructure/services/recording-mailer.service.ts"
   },
   "scripts": {
     "build": "tsc --noEmit",