fix: remove medium theme, fix navbar re-render, fix Node.js env loading

- Remove 'medium' theme from dashboard and marketplace; keep only light/dark
- Marketplace: move public pages into (public)/ route group so header/footer
  persist across navigations without re-rendering (eliminates usePathname)
- MarketplaceShell is now a pure context provider; chrome lives in
  (public)/layout.tsx which Next.js holds stable across navigations
- WorkspaceFrame: remove history.replaceState and standalone-route logic
- Docker API: bypass npm run dev to avoid node --env-file in containers
- Add scripts/run-with-env-file.cjs for Node.js < 20.6 compatibility;
  update apps/api/package.json dev script to use it

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/marketplace/src/app/(public)/footer/[slug]/page.tsx

@@ -0,0 +1,21 @@
+import { notFound } from 'next/navigation'
+import FooterContentPage from '@/components/FooterContentPage'
+import { footerPageSlugs, isFooterPageSlug } from '@/lib/footerContent'
+
+export function generateStaticParams() {
+  return footerPageSlugs.map((slug) => ({ slug }))
+}
+
+export default function FooterPage({
+  params,
+}: {
+  params: { slug: string }
+}) {
+  const { slug } = params
+
+  if (!isFooterPageSlug(slug)) {
+    notFound()
+  }
+
+  return <FooterContentPage slug={slug} />
+}