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/api/package.json

@@ -4,7 +4,7 @@
   "private": true,
   "scripts": {
     "predev": "npm run build --workspace @rentaldrivego/types",
-    "dev": "node --env-file=../../.env.local ../../node_modules/.bin/ts-node-dev --respawn --transpile-only src/index.ts",
+    "dev": "node ../../scripts/run-with-env-file.cjs ../../.env.local ../../node_modules/.bin/ts-node-dev --respawn --transpile-only src/index.ts",
     "prebuild": "npm run build --workspace @rentaldrivego/types",
     "build": "tsc",
     "prestart": "npm run build --workspace @rentaldrivego/types",