Reduce Docker build memory use on small VPS

next.config.ts

@@ -1,12 +1,18 @@
 import type { NextConfig } from "next";
 import { withWorkflow } from "workflow/next";
+// Set only by build-docker.mjs after the separate type check has succeeded.
+const dockerTypechecked = process.env.MINEGEO_DOCKER_TYPECHECKED === "1";
 const config: NextConfig = {
   poweredByHeader: false,
   cacheMaxMemorySize: 16 * 1024 * 1024,
   enablePrerenderSourceMaps: false,
+  typescript: { ignoreBuildErrors: dockerTypechecked },
   experimental: {
     cpus: 1,
     preloadEntriesOnStart: false,
+    ...(dockerTypechecked
+      ? { webpackBuildWorker: true, webpackMemoryOptimizations: true }
+      : {}),
   },
   outputFileTracingIncludes: { "/downloads": ["./public/tools/**/*.jar"] },
   serverExternalPackages: ["pg"],