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>

docker-compose.dev.yml

@@ -92,7 +92,7 @@ services:
       - .env.docker.dev
     environment:
       FILE_STORAGE_ROOT: /var/lib/rentaldrivego/storage
-    command: ["npm", "run", "dev", "--workspace", "@rentaldrivego/api"]
+    command: ["sh", "-c", "npm run build --workspace @rentaldrivego/types && cd /app/apps/api && exec /app/node_modules/.bin/ts-node-dev --respawn --transpile-only src/index.ts"]
     ports:
       - "4000:4000"
     volumes: