perf: optimize portfolio runtime delivery

Replace the blocking asset loader with progressive rendering, defer expensive media and Three.js work, and reduce hydration and animation costs. Move deployment from a static Nginx export to the standalone Next.js runtime with optimized dynamic images.

DEPLOYMENT.md

@@ -49,9 +49,27 @@ Replace `deploy:deploy` and `/srv/portfolio` with the values used for
 `DEPLOY_USER` and `DEPLOY_PATH`. Add the public half of `DEPLOY_SSH_KEY` to the
 deployment user's `~/.ssh/authorized_keys`.
 
-The container joins `caddy_proxy` under the `static-site` service name. Caddy
-must also join that network and proxy to `static-site:80`. No host port is
-published by this project.
+The standalone Next.js container joins `caddy_proxy` under the `portfolio-app`
+service name. Caddy must also join that network and proxy to
+`portfolio-app:3000`. No host port is published by this project.
+
+A minimal Caddy route is:
+
+```caddyfile
+portfolio.example.com {
+  reverse_proxy portfolio-app:3000
+}
+```
+
+Caddy forwards the browser's `Accept` header by default; keep that behavior so
+Next.js can negotiate WebP responses. Do not replace the cache headers emitted
+for `/_next/image`. The named `next-image-cache` volume persists `.next/cache`
+between container replacements so optimized variants can be reused.
+
+The application expects immutable media URLs. When an admin or future upload
+workflow replaces an image, write it to a UUID or content-versioned URL instead
+of overwriting the previous object at the same URL. Next.js has no per-image
+optimizer-cache invalidation API.
 
 ## Manual deployment
 
@@ -64,3 +82,10 @@ docker compose --project-name portfolio up --detach --build --remove-orphans
 Old versioned release directories are deliberately retained for rollback. They
 can be removed manually after a newer release has been proven stable; keep the
 directory referenced by the `current` symlink.
+
+## Runtime verification
+
+The production image contains `.next/standalone`, `.next/static`, and `public`,
+and runs the generated `server.js` with Node.js 22 on port 3000. CI smoke-tests
+the English and Persian routes, a built static asset, and `/_next/image` with
+WebP negotiation before deployment.