fix(web-next): enforce manifest rate limits on the production path

bindAllProduction injected NoopRateLimit, so the sign-in budgets the
auth manifest declares were never enforced in production (audit finding
A4/B3). The production ctx now binds InMemoryRateLimit seeded from the
manifest's rateLimit budgets (manifest stays the source of truth);
dev-seed intentionally keeps Noop so local iteration never throttles.
A regression test drives sign-in through the REAL auth production
binder + app router and asserts the 6th failed attempt returns
TOO_MANY_REQUESTS while other IPs stay unaffected. In-memory counters
are per-process; multi-instance deployments need a shared IRateLimit
backend.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web-next/src/server/bind-production.rate-limit.test.ts

@@ -0,0 +1,97 @@
+// A4/B3 regression: the PRODUCTION binder must enforce the auth manifest's
+// rate-limit budgets. Unlike bind-production.test.ts (which mocks every
+// feature binder), this file runs the REAL auth production binder against a
+// stubbed Payload local API and drives sign-in through the app router.
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+vi.mock("@repo/core-cms", () => ({ default: Promise.resolve({}) }));
+
+const payloadStub = vi.hoisted(() => ({
+  secret: "test-secret",
+  jobs: { queue: vi.fn() },
+  // No user ever matches → every sign-in fails and consumes budget.
+  find: vi.fn(async () => ({ docs: [] })),
+  findByID: vi.fn(async () => null),
+  create: vi.fn(async ({ data }: { data: Record<string, unknown> }) => data),
+}));
+vi.mock("payload", () => ({ getPayload: vi.fn(async () => payloadStub) }));
+
+// Other features are irrelevant here — mock their binders so this test only
+// boots the auth production path.
+vi.mock("@repo/blog/di/bind-production", () => ({
+  bindProductionBlog: vi.fn(),
+}));
+vi.mock("@repo/marketing-pages/di/bind-production", () => ({
+  bindProductionMarketingPages: vi.fn(),
+}));
+vi.mock("@repo/navigation/di/bind-production", () => ({
+  bindProductionNavigation: vi.fn(),
+}));
+vi.mock("@repo/media/di/bind-production", () => ({
+  bindProductionMedia: vi.fn(),
+}));
+
+describe("bindAllProduction rate limiting (A4/B3)", () => {
+  beforeEach(() => {
+    vi.resetModules();
+    vi.clearAllMocks();
+  });
+
+  it("returns TOO_MANY_REQUESTS once the manifest ip budget is exhausted", async () => {
+    const { bindAllProduction } = await import("./bind-production");
+    await bindAllProduction();
+
+    const { appRouter } = await import("@repo/core-api");
+    const { authManifest } = await import("@repo/auth");
+    const caller = appRouter.createCaller({ clientIp: "203.0.113.7" });
+
+    const attempt = () =>
+      caller.auth.signIn({ username: "ghost", password: "wrong-password" });
+
+    // The manifest is the budget's source of truth: 5 failed attempts pass
+    // through (UNAUTHORIZED), the 6th trips the ip bucket.
+    const ipBudget = authManifest.useCases.signIn.rateLimit.find(
+      (b) => b.name === "ip",
+    );
+    expect(ipBudget).toBeDefined();
+    for (let i = 0; i < ipBudget!.budget; i++) {
+      await expect(attempt()).rejects.toMatchObject({ code: "UNAUTHORIZED" });
+    }
+    await expect(attempt()).rejects.toMatchObject({
+      code: "TOO_MANY_REQUESTS",
+    });
+  });
+
+  it("keeps other client IPs unaffected by an exhausted bucket", async () => {
+    const { bindAllProduction } = await import("./bind-production");
+    await bindAllProduction();
+
+    const { appRouter } = await import("@repo/core-api");
+    const { authManifest } = await import("@repo/auth");
+
+    const throttled = appRouter.createCaller({ clientIp: "198.51.100.9" });
+    const ipBudget = authManifest.useCases.signIn.rateLimit.find(
+      (b) => b.name === "ip",
+    )!;
+    for (let i = 0; i < ipBudget.budget; i++) {
+      await expect(
+        throttled.auth.signIn({
+          username: `user${i}x`,
+          password: "wrong-password",
+        }),
+      ).rejects.toMatchObject({ code: "UNAUTHORIZED" });
+    }
+    await expect(
+      throttled.auth.signIn({ username: "user0x", password: "wrong-password" }),
+    ).rejects.toMatchObject({ code: "TOO_MANY_REQUESTS" });
+
+    // A different IP still gets an ordinary auth failure, not a throttle.
+    const fresh = appRouter.createCaller({ clientIp: "192.0.2.55" });
+    await expect(
+      fresh.auth.signIn({
+        username: "someoneelse",
+        password: "wrong-password",
+      }),
+    ).rejects.toMatchObject({ code: "UNAUTHORIZED" });
+  });
+});