fix: bootstrap admin CSRF tokens

src/app/admin/layout.tsx

@@ -17,11 +17,11 @@ import {
 	parseAdminNavConfig,
 } from "@/lib/admin-nav-config";
 import { db, User } from "@/lib/db";
-import { setCsrfCookie } from "@/lib/foundation/security";
+import { readCsrfCookieToken } from "@/lib/foundation/security";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { siteSettings } from "@/lib/services/site-settings";
 
-// Request-time auth: requireStaff, CSRF cookie, and optional 2FA gate cannot be
+// Request-time auth, existing CSRF cookie, and optional 2FA gate cannot be
 // statically rendered. Child admin pages inherit this — leaf force-dynamic is redundant.
 export const dynamic = "force-dynamic";
 
@@ -31,12 +31,7 @@ export default async function AdminLayout({
 	children: ReactNode;
 }) {
 	const staff = await requireStaff();
-	let csrfToken = "";
-	try {
-		csrfToken = await setCsrfCookie();
-	} catch {
-		csrfToken = "";
-	}
+	const csrfToken = await readCsrfCookieToken();
 	if (await siteSettings.getBool("force_staff_2fa", false)) {
 		const u = await db
 			.select({ twoFactorConfirmedAt: User.twoFactorConfirmedAt })

src/app/api/admin/csrf/route.test.ts

@@ -0,0 +1,51 @@
+import { NextRequest } from "next/server";
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+const mocks = vi.hoisted(() => ({
+	setCsrfCookie: vi.fn(),
+}));
+
+vi.mock("@/lib/api-handler", () => ({
+	withAdmin:
+		(_options: unknown, handler: (...args: never[]) => unknown) =>
+		(...args: never[]) =>
+			handler(...args),
+}));
+
+vi.mock("@/lib/foundation/security", () => ({
+	setCsrfCookie: mocks.setCsrfCookie,
+}));
+
+import { GET } from "./route";
+
+describe("admin CSRF bootstrap route", () => {
+	beforeEach(() => {
+		mocks.setCsrfCookie.mockReset();
+	});
+
+	it("returns the token written by the route handler without caching", async () => {
+		const token = "a".repeat(64);
+		mocks.setCsrfCookie.mockResolvedValue(token);
+
+		const response = await GET(
+			new NextRequest("http://localhost/api/admin/csrf"),
+		);
+
+		expect(response.status).toBe(200);
+		expect(response.headers.get("cache-control")).toBe("no-store");
+		expect(await response.json()).toEqual({ ok: true, token });
+	});
+
+	it("fails closed when the cookie cannot be written", async () => {
+		mocks.setCsrfCookie.mockResolvedValue("");
+
+		const response = await GET(
+			new NextRequest("http://localhost/api/admin/csrf"),
+		);
+
+		expect(response.status).toBe(500);
+		expect(await response.json()).toEqual({
+			error: "Unable to initialize CSRF token",
+		});
+	});
+});

src/app/api/admin/csrf/route.ts

@@ -0,0 +1,12 @@
+import { withAdmin } from "@/lib/api-handler";
+import { apiError, apiOk } from "@/lib/api-response";
+import { setCsrfCookie } from "@/lib/foundation/security";
+
+export const GET = withAdmin({ requireCsrf: false }, async () => {
+	const token = await setCsrfCookie();
+	if (!token) return apiError("Unable to initialize CSRF token", 500);
+
+	const response = apiOk({ token });
+	response.headers.set("Cache-Control", "no-store");
+	return response;
+});

src/app/mod/layout.tsx

@@ -17,7 +17,7 @@ import { LanguageSwitcher } from "@/components/language-switcher";
 import { ThemeSwitcher } from "@/components/theme-switcher";
 import { requireMod } from "@/lib/admin/guard";
 import { db, User } from "@/lib/db";
-import { setCsrfCookie } from "@/lib/foundation/security";
+import { readCsrfCookieToken } from "@/lib/foundation/security";
 import { canAccess, getAdminContext, PERMS } from "@/lib/permissions";
 import { siteSettings } from "@/lib/services/site-settings";
 
@@ -25,12 +25,7 @@ export const dynamic = "force-dynamic";
 
 export default async function ModLayout({ children }: { children: ReactNode }) {
 	const staff = await requireMod();
-	let csrfToken = "";
-	try {
-		csrfToken = await setCsrfCookie();
-	} catch {
-		csrfToken = "";
-	}
+	const csrfToken = await readCsrfCookieToken();
 	if (await siteSettings.getBool("force_staff_2fa", false)) {
 		const [u] = await db
 			.select({ twoFactorConfirmedAt: User.twoFactorConfirmedAt })