Serve with Node/Express instead of nginx (matches working astroreal pattern)

- Add server.js: Express serves dist/ + injects env (GA_ID, FORM_EMAIL, GMAP) at runtime
- Container port now 4321 (identical to moreminimore-astroreal that deploys on EasyPanel)
- Remove nginx.conf + entrypoint.sh (no longer needed); Dockerfile uses node server.js
- Verified: pnpm build + node server.js -> all 40 pages serve 200, env injected, 0 leftovers

.dockerignore

@@ -4,12 +4,6 @@ dist/
 .astro/
 pnpm-debug.log*
 
-# Python tooling (not needed in image)
-__pycache__/
-*.pyc
-mirror_log*.txt
-*.py
-
 # Secrets / local env
 .env
 .env.*
@@ -19,6 +13,3 @@ mirror_log*.txt
 .git
 .gitignore
 README.md
-
-# Original static clone (superseded by src/pages + public)
-site/