fix(build): make the production build pass, and stop it eating 20GB

`next build` had never completed on this host, so three real defects were
sitting in the tree untested. All three are now fixed and the build is green.

- The build was not memory-bound the way it looked. Turbopack's builder reached
  20.5GB RSS and died, and raising `--max-old-space-size` could never have
  helped: that flag caps the V8 heap, while the 20GB sat in Turbopack's own Rust
  allocator. The first symptom was misleading because the process doing the
  allocating is a grandchild of `npx`, so watching the direct child shows a
  95MB shim the whole time. Building with `--webpack` puts the build back under
  the JS heap, where the flag actually applies: peak 5.9GB, 150s, exit 0.

- withAdmin's second parameter was typed `{ params?: ... }` and given a `= {}`
  default, which made it optional and `RouteContext | undefined`. Next's
  generated route types assert that argument against `ParamCheck<RouteContext>`
  and reject it, across 113 route files. `tsc --noEmit` cannot see this, because
  Next only adds `.next/types` to the project during a production build — so the
  type check that everyone runs locally was structurally incapable of catching
  the only type error that blocks a deploy. `params` is now required, which is
  also what the code already assumed: it is awaited with no guard. The 35 test
  call sites that invoked a handler with one argument now pass a real context,
  and the await got a guard so a direct internal call cannot turn a missing
  context into a 500.

- `src/app/api/admin/import/furni/route.ts` re-exported `ensureDirectories` and
  `importSingleFurni` for "backward compatibility" that nothing used; the batch
  route imports from `@/lib/services/furni-import` directly. Next rejects any
  value export from a route module that is not an HTTP verb or config, so this
  had been breaking the build for as long as it existed. Removed.

- `isomorphic-dompurify` builds its server-side DOM through jsdom. Bundled, that
  pulls jsdom's `browser/default-stylesheet.css` into the server chunk, where the
  path no longer resolves, and page-data collection dies with ENOENT on every
  page that sanitizes HTML. Marked external so Node resolves it from
  node_modules and the standalone tracer includes it.

The remaining build warning is a pre-existing circular dependency between
chunks that share the webpack runtime. It costs hash reuse, not correctness, and
is left alone rather than churned here.

Verified: build exit 0, 276 static pages generated, 3223 tests pass, tsc and
biome clean.

next.config.ts

@@ -36,7 +36,18 @@ const nextConfig: NextConfig = {
 	reactStrictMode: true,
 	compress: true,
 	productionBrowserSourceMaps: false,
-	serverExternalPackages: ["lzma-wasm", "sharp", "pino", "pino-pretty"],
+	// `isomorphic-dompurify` builds a DOM through jsdom on the server. Bundled,
+	// it drags jsdom's `browser/default-stylesheet.css` into the server chunk,
+	// where the path no longer exists and page-data collection dies with ENOENT
+	// on any page that sanitizes HTML. Kept external, Node resolves it from
+	// node_modules at runtime and the standalone output traces it in.
+	serverExternalPackages: [
+		"lzma-wasm",
+		"sharp",
+		"pino",
+		"pino-pretty",
+		"isomorphic-dompurify",
+	],
 
 	async redirects() {
 		return [

src/app/api/admin/catalog-export/config/route.test.ts

@@ -17,6 +17,7 @@ vi.mock("@/lib/services/catalog-git-managed", () => ({
 }));
 
 import { PERMS } from "@/lib/permission-slugs";
+import { emptyRouteContext } from "@/test/route-context";
 import { GET, POST } from "./route";
 
 let root: string;
@@ -48,7 +49,7 @@ describe("Gitea configuration endpoint", () => {
 		expect(mocks.guard).toHaveBeenCalledWith({
 			permission: PERMS.SETTINGS_EDIT,
 		});
-		const response = await POST(request());
+		const response = await POST(request(), emptyRouteContext());
 		expect(response.status).toBe(200);
 		const data = await response.json();
 		expect(data.hasToken).toBe(true);
@@ -61,27 +62,29 @@ describe("Gitea configuration endpoint", () => {
 			await (
 				await GET(
 					new NextRequest("http://localhost/api/admin/catalog-export/config"),
+					emptyRouteContext(),
 				)
 			).text(),
 		).not.toContain(input.token);
 	});
 	it("does not save unverified enabled configurations", async () => {
 		mocks.connection.mockRejectedValue(new Error("Cannot connect"));
-		expect((await POST(request())).status).toBe(400);
+		expect((await POST(request(), emptyRouteContext())).status).toBe(400);
 		expect(await fs.readdir(root)).toEqual([]);
 	});
 	it("rejects configuration changes during an export", async () => {
 		await fs.writeFile(path.join(root, "worker.lock"), "active");
-		expect((await POST(request())).status).toBe(409);
+		expect((await POST(request(), emptyRouteContext())).status).toBe(409);
 		expect(mocks.connection).not.toHaveBeenCalled();
 	});
 	it("prevents moving queued changes to a different repository", async () => {
-		await POST(request());
+		await POST(request(), emptyRouteContext());
 		await fs.writeFile(path.join(root, "change.pending"), "pending");
 		expect(
 			(
 				await POST(
 					request({ ...input, remote: "https://other.example/user/repo" }),
+					emptyRouteContext(),
 				)
 			).status,
 		).toBe(409);

src/app/api/admin/catalog/search/route.test.ts

@@ -19,6 +19,7 @@ vi.mock("@/lib/api-handler", () => ({
 }));
 
 import { PERMS } from "@/lib/permissions";
+import { emptyRouteContext } from "@/test/route-context";
 import { GET } from "./route";
 
 beforeEach(() => {
@@ -34,6 +35,7 @@ describe("catalog search route", () => {
 			new NextRequest(
 				"https://cms.test/api/admin/catalog/search?catalog=bc&q=chair",
 			),
+			emptyRouteContext(),
 		);
 		expect(search).toHaveBeenCalledWith("bc", "chair");
 		expect(await response.json()).toEqual({ ok: true, results: [] });
@@ -42,6 +44,7 @@ describe("catalog search route", () => {
 		search.mockRejectedValue(Error("Invalid search"));
 		const response = await GET(
 			new NextRequest("https://cms.test/api/admin/catalog/search?q=a"),
+			emptyRouteContext(),
 		);
 		expect(response.status).toBe(400);
 		expect(await response.json()).toEqual({ error: "Invalid search" });

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

@@ -16,6 +16,7 @@ vi.mock("@/lib/foundation/security", () => ({
 	setCsrfCookie: mocks.setCsrfCookie,
 }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { GET } from "./route";
 
 describe("admin CSRF bootstrap route", () => {
@@ -29,6 +30,7 @@ describe("admin CSRF bootstrap route", () => {
 
 		const response = await GET(
 			new NextRequest("http://localhost/api/admin/csrf"),
+			emptyRouteContext(),
 		);
 
 		expect(response.status).toBe(200);
@@ -41,6 +43,7 @@ describe("admin CSRF bootstrap route", () => {
 
 		const response = await GET(
 			new NextRequest("http://localhost/api/admin/csrf"),
+			emptyRouteContext(),
 		);
 
 		expect(response.status).toBe(500);

src/app/api/admin/import/furni/route.ts

@@ -47,11 +47,10 @@ import { streamImportResponse } from "@/lib/services/import/core/single-response
 import { rcon } from "@/lib/services/rcon";
 import { convertSwfToNitro } from "@/lib/services/swf-to-nitro";
 
-// Re-export for batch route backward compatibility
+// No value re-exports here. A route module may only export HTTP verbs and
-export {
+// config, and Next's generated types reject anything else — `tsc --noEmit` does
-	ensureDirectories,
+// not see it, because the check lives in `.next/types`. Both of these are
-	importSingleFurni,
+// imported from `@/lib/services/furni-import` where they are actually needed.
-} from "@/lib/services/furni-import";
 export type { ImportSingleResult } from "@/types/furni";
 
 import type { ImportSingleResult } from "@/types/furni";

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

@@ -46,6 +46,7 @@ import {
 	WebsiteTicket,
 } from "@/lib/db";
 import { PERMS } from "@/lib/permission-slugs";
+import { emptyRouteContext } from "@/test/route-context";
 import { GET } from "./route";
 
 const calls: {
@@ -97,6 +98,7 @@ const search = (q: string) =>
 		new NextRequest(
 			`https://cms.test/api/admin/search?q=${encodeURIComponent(q)}`,
 		),
+		emptyRouteContext(),
 	);
 
 describe("unified admin search", () => {

src/app/api/admin/studio/inspect/route.test.ts

@@ -26,6 +26,7 @@ vi.mock("@/lib/services/furni-asset-dirs", () => ({
 }));
 vi.mock("node:fs", () => ({ promises: { stat: mocks.stat } }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { POST } from "./route";
 
 const request = (classnames: unknown) =>
@@ -48,7 +49,9 @@ describe("furniture inspection", () => {
 		});
 	});
 	it("rejects path traversal before reading data", async () => {
-		expect((await POST(request(["../secret"]))).status).toBe(400);
+		expect(
+			(await POST(request(["../secret"]), emptyRouteContext())).status,
+		).toBe(400);
 		expect(mocks.execute).not.toHaveBeenCalled();
 		expect(mocks.stat).not.toHaveBeenCalled();
 	});
@@ -70,7 +73,7 @@ describe("furniture inspection", () => {
 				[{ classname: "chair*2", id: 5, pageId: 7, credits: 3, points: 0 }],
 				[],
 			]);
-		const response = await POST(request(["chair*2"]));
+		const response = await POST(request(["chair*2"]), emptyRouteContext());
 		const body = await response.json();
 		expect(body.items[0].sql[0].id).toBe(90);
 		expect(body.items[0].catalog[0].pageId).toBe(7);
@@ -83,7 +86,9 @@ describe("furniture inspection", () => {
 	it("distinguishes unreadable data and denied assets from missing files", async () => {
 		mocks.read.mockRejectedValue(new Error("unreadable"));
 		mocks.stat.mockRejectedValue({ code: "EACCES" });
-		const body = await (await POST(request(["chair"]))).json();
+		const body = await (
+			await POST(request(["chair"]), emptyRouteContext())
+		).json();
 		expect(body.items[0].furnidataReadable).toBe(false);
 		expect(body.items[0].icon.exists).toBeNull();
 		expect(body.items[0].nitro.exists).toBeNull();
@@ -93,7 +98,7 @@ describe("furniture inspection", () => {
 			roomitemtypes: { furnitype: {} },
 			wallitemtypes: { furnitype: [null] },
 		});
-		const response = await POST(request(["chair"]));
+		const response = await POST(request(["chair"]), emptyRouteContext());
 		expect(response.status).toBe(200);
 		expect((await response.json()).items[0].furnidataReadable).toBe(false);
 	});
@@ -136,7 +141,9 @@ describe("furniture inspection", () => {
 				return { size: 256, isFile: () => true };
 			throw { code: "ENOENT" };
 		});
-		const result = await (await POST(request(["recycler_kintsugiB"]))).json();
+		const result = await (
+			await POST(request(["recycler_kintsugiB"]), emptyRouteContext())
+		).json();
 		expect(result.items[0].sql[0].id).toBe(2000037258);
 		expect(result.items[0].catalog).toHaveLength(1);
 		expect(result.items[0].furnidata).toHaveLength(1);

src/app/api/admin/studio/nitro-quality/route.test.ts

@@ -16,6 +16,7 @@ vi.mock("@/lib/services/furni-asset-dirs", () => ({
 	getFurniAssetDirs: async () => ({ nitroDir: "/nitro" }),
 }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { GET } from "./route";
 
 const request = (query: string) =>
@@ -40,11 +41,13 @@ it("requires import permission", () =>
 		permission: PERMS.ASSETS_IMPORT,
 	}));
 it("rejects path traversal before reading disk", async () => {
-	expect((await GET(request("classname=../secret"))).status).toBe(400);
+	expect(
+		(await GET(request("classname=../secret"), emptyRouteContext())).status,
+	).toBe(400);
 	expect(mocks.read).not.toHaveBeenCalled();
 });
 it("reports both scales from the actual bundle", async () => {
-	const response = await GET(request("classname=chair"));
+	const response = await GET(request("classname=chair"), emptyRouteContext());
 	expect(
 		(await response.json()).report.scales.map(
 			(s: { state: string }) => s.state,
@@ -52,7 +55,10 @@ it("reports both scales from the actual bundle", async () => {
 	).toEqual(["present", "missing"]);
 });
 it("extracts the actual sprite dimensions without resizing", async () => {
-	const response = await GET(request("classname=chair&asset=chair_32_a_0_0"));
+	const response = await GET(
+		request("classname=chair&asset=chair_32_a_0_0"),
+		emptyRouteContext(),
+	);
 	expect(response.status).toBe(200);
 	const meta = await sharp(
 		Buffer.from(await response.arrayBuffer()),
@@ -60,5 +66,8 @@ it("extracts the actual sprite dimensions without resizing", async () => {
 	expect([meta.width, meta.height]).toEqual([2, 3]);
 });
 it("rejects an unknown sprite instead of returning a different one", async () => {
-	expect((await GET(request("classname=chair&asset=other"))).status).toBe(404);
+	expect(
+		(await GET(request("classname=chair&asset=other"), emptyRouteContext()))
+			.status,
+	).toBe(404);
 });

src/app/api/admin/studio/nitro-scale32/route.test.ts

@@ -38,6 +38,7 @@ vi.mock("@/lib/services/swf/nitro-builder", () => ({
 	parseNitroBundle: () => ({ json: { assets: {} } }),
 }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { POST } from "./route";
 
 const original = Buffer.from("original"),
@@ -59,21 +60,31 @@ beforeEach(() => {
 	});
 });
 it("preview does not write anything", async () => {
-	expect((await POST(request({ action: "preview" }))).status).toBe(200);
+	expect(
+		(await POST(request({ action: "preview" }), emptyRouteContext())).status,
+	).toBe(200);
 	expect(mocks.write).not.toHaveBeenCalled();
 });
 it("rejects stale source before generation or writes", async () => {
 	expect(
-		(await POST(request({ action: "apply", expectedHash: hash(generated) })))
+		(
-			.status,
+			await POST(
+				request({ action: "apply", expectedHash: hash(generated) }),
+				emptyRouteContext(),
+			)
+		).status,
 	).toBe(409);
 	expect(mocks.generate).not.toHaveBeenCalled();
 	expect(mocks.write).not.toHaveBeenCalled();
 });
 it("backs up the original before replacing the bundle", async () => {
 	expect(
-		(await POST(request({ action: "apply", expectedHash: hash(original) })))
+		(
-			.status,
+			await POST(
+				request({ action: "apply", expectedHash: hash(original) }),
+				emptyRouteContext(),
+			)
+		).status,
 	).toBe(200);
 	expect(mocks.write.mock.calls[0][1]).toEqual(original);
 	expect(mocks.write.mock.calls[1][1]).toEqual(generated);
@@ -89,6 +100,7 @@ it("restores the exact backup after checking the current hash", async () => {
 					expectedHash: hash(generated),
 					backupHash: hash(original),
 				}),
+				emptyRouteContext(),
 			)
 		).status,
 	).toBe(200);
@@ -97,8 +109,12 @@ it("restores the exact backup after checking the current hash", async () => {
 it("does not replace the live file when backup writing fails", async () => {
 	mocks.write.mockRejectedValueOnce(Error("disk full"));
 	expect(
-		(await POST(request({ action: "apply", expectedHash: hash(original) })))
+		(
-			.status,
+			await POST(
+				request({ action: "apply", expectedHash: hash(original) }),
+				emptyRouteContext(),
+			)
+		).status,
 	).toBe(422);
 	expect(mocks.rename).not.toHaveBeenCalled();
 });

src/app/api/admin/studio/source-assets/route.test.ts

@@ -22,6 +22,7 @@ vi.mock("@/lib/services/furniture-source-assets", () => ({
 	inspectSourceAssets: mocks.inspect,
 }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { POST } from "./route";
 
 const item = {
@@ -59,12 +60,19 @@ it.each([
 	[{ ...item, revision: -1 }],
 	[null],
 ])("rejects invalid items before network checks: %j", async (items) => {
-	expect((await POST(request({ items }))).status).toBe(400);
+	expect((await POST(request({ items }), emptyRouteContext())).status).toBe(
+		400,
+	);
 	expect(mocks.inspect).not.toHaveBeenCalled();
 });
 it("rejects unknown configured sources", async () => {
 	expect(
-		(await POST(request({ items: [item], sourceId: "missing" }))).status,
+		(
+			await POST(
+				request({ items: [item], sourceId: "missing" }),
+				emptyRouteContext(),
+			)
+		).status,
 	).toBe(404);
 	expect(mocks.inspect).not.toHaveBeenCalled();
 });
@@ -77,6 +85,7 @@ it("uses server source configuration instead of client URLs", async () => {
 			sourceId: "custom",
 			nitroBaseUrl: "https://untrusted.example",
 		}),
+		emptyRouteContext(),
 	);
 	expect(response.status).toBe(200);
 	expect(mocks.inspect).toHaveBeenCalledWith(item, [], source);

src/lib/api-handler-correlation.test.ts

@@ -32,6 +32,7 @@ vi.mock("@/lib/services/catalog-git-queue", () => ({
 	beginCatalogExport: vi.fn(),
 }));
 
+import { emptyRouteContext } from "@/test/route-context";
 import { withAdmin } from "./api-handler";
 
 const request = () =>
@@ -50,7 +51,10 @@ describe("admin API correlation", () => {
 			await Promise.resolve();
 			return NextResponse.json(getOperationContext());
 		});
-		const [a, b] = await Promise.all([handler(request()), handler(request())]);
+		const [a, b] = await Promise.all([
+			handler(request(), emptyRouteContext()),
+			handler(request(), emptyRouteContext()),
+		]);
 		expect(a.headers.get("x-operation-id")).not.toBe("forged-client-id");
 		expect(a.headers.get("x-operation-id")).not.toBe(
 			b.headers.get("x-operation-id"),
@@ -71,7 +75,7 @@ describe("admin API correlation", () => {
 			response.cookies.set("second", "two", { httpOnly: true });
 			return response;
 		});
-		const response = await handler(request());
+		const response = await handler(request(), emptyRouteContext());
 		expect(response.status).toBe(307);
 		expect(response.headers.get("location")).toBe(
 			"https://hotel.test/admin/users",
@@ -104,7 +108,7 @@ describe("admin API correlation", () => {
 					},
 				),
 		);
-		const response = await handler(request());
+		const response = await handler(request(), emptyRouteContext());
 		expect(response.headers.get("content-type")).toBe("text/event-stream");
 		expect(response.headers.get("x-custom")).toBe("retained");
 		const body = response.text();
@@ -121,17 +125,17 @@ describe("admin API correlation", () => {
 			throw new Error("private-database-message");
 		});
 		state.authorized = false;
-		const unauthorized = await handler(request());
+		const unauthorized = await handler(request(), emptyRouteContext());
 		expect(unauthorized.status).toBe(401);
 		expect(state.record).not.toHaveBeenCalled();
 		expect(unauthorized.headers.get("x-operation-id")).toBeTruthy();
 		state.authorized = true;
 		state.permitted = false;
-		const forbidden = await handler(request());
+		const forbidden = await handler(request(), emptyRouteContext());
 		expect(forbidden.status).toBe(403);
 		expect(forbidden.headers.get("x-operation-id")).toBeTruthy();
 		state.permitted = true;
-		const failed = await handler(request());
+		const failed = await handler(request(), emptyRouteContext());
 		expect(failed.status).toBe(500);
 		expect(failed.headers.get("x-operation-id")).toBeTruthy();
 		expect(await failed.json()).toEqual({

src/lib/api-handler.ts

@@ -25,7 +25,11 @@ const MUTATING_METHODS = new Set(["POST", "PUT", "PATCH", "DELETE"]);
 const MAX_BODY_BYTES = 10 * 1024 * 1024; // 10 MB
 
 type AdminContext = NonNullable<Awaited<ReturnType<typeof getApiAdminContext>>>;
-type RouteContext = { params?: Promise<Record<string, string | string[]>> };
+// Next 15+ passes `params` as a promise and its generated route types require it
+// to be present, so this is deliberately not optional. `routeContext.params` is
+// awaited below without a guard, so an optional type would have been a lie
+// anyway. A route with no dynamic segments still receives `Promise<{}>`.
+type RouteContext = { params: Promise<Record<string, string | string[]>> };
 type AdminHandler = (
 	request: NextRequest,
 	context: AdminContext,
@@ -40,7 +44,16 @@ export function withAdmin(
 	},
 	handler: AdminHandler,
 ) {
-	return async (request: NextRequest, routeContext: RouteContext = {}) => {
+	// No default value here on purpose. `RouteContext` already has an optional
+	// `params`, so `{}` was always assignable and the default only widened the
+	// parameter to `RouteContext | undefined`. Next's generated route types assert
+	// the second argument against `ParamCheck<RouteContext>`, and the `undefined`
+	// fails that check. `tsc --noEmit` does not see it, because Next only adds
+	// `.next/types` to the project during a production build.
+	// Deliberately no default. A parameter with a default is optional in the
+	// signature, which makes its type `RouteContext | undefined` and fails Next's
+	// `ParamCheck`. Tests that call a handler directly pass `emptyRouteContext()`.
+	return async (request: NextRequest, routeContext: RouteContext) => {
 		const store = createStore("unknown" as IpAddress);
 		const { value: response, metrics } = await collectPerformance(() =>
 			runWithStore(store, async () => {
@@ -153,7 +166,11 @@ export function withAdmin(
 				operationId: store.requestId,
 				route: routeTemplate(
 					request.nextUrl.pathname,
-					await routeContext.params,
+					// Next always passes a context, and the type requires it, so
+					// this is only a guard against a direct internal call. The
+					// worst case is a slightly less specific metric label, which
+					// is not worth a 500.
+					await routeContext?.params,
 				),
 				method: request.method,
 				status: response.status,

src/test/route-context.ts

@@ -0,0 +1,15 @@
+/**
+ * The route context Next hands to a route handler, for tests that call one
+ * directly. `params` has been a promise since Next 15, and a route with no
+ * dynamic segments still receives an empty one, so this is the real call
+ * contract rather than a convenience shim.
+ *
+ * Deliberately self-contained: it does not import from `@/lib/api-handler`,
+ * because route tests routinely `vi.mock` that module, and pulling a value out
+ * of a mock would fail at runtime.
+ */
+export function emptyRouteContext(): {
+	params: Promise<Record<string, string | string[]>>;
+} {
+	return { params: Promise.resolve({}) };
+}