Reduce Docker build memory use on small VPS

docs/dokploy-deployment.md

@@ -43,6 +43,54 @@ Also set the following in Dokploy's regular runtime environment:
 Add any optional production variables from `.env.example` in Dokploy's
 environment settings. Do not upload `.env.local` or add it to the repository.
 
+## Building on a 2 GiB VPS
+
+The Dockerfile uses `npm run build:docker`. It generates route types and runs
+the full TypeScript check in a separate process before compiling with Webpack.
+Next.js skips its duplicate TypeScript check only after the separate check
+succeeds. The Docker build enables Webpack's build worker and memory
+optimizations, and keeps page collection at one worker. Each build Node process
+has a 640 MiB JavaScript heap ceiling; this is not a limit on the total memory
+used by all processes or native libraries.
+
+Dependencies are installed once, then pruned after compilation. The dependency
+installation for the final image no longer runs independently alongside the
+application build. Normal `npm run build` retains its usual type checking and
+bundler behavior. See Next.js's [memory usage
+guide](https://nextjs.org/docs/app/guides/memory-usage) for the build options.
+
+In Dokploy, keep builds concurrency at **1** on this VPS. Dokploy, PostgreSQL,
+Redis, Traefik, the running application, and the new build share the host's RAM.
+Avoid starting a panorama render during a deployment. Application runtime
+resource limits do not necessarily limit the Docker image build.
+
+If the host freezes, capture these read-only diagnostics from the VPS shell
+before retrying. They print resource figures and Dokploy container state without
+environment values, API keys, private addresses, or repository names:
+
+```sh
+free -m
+df -h /
+vmstat 1 5
+journalctl -k --since '30 minutes ago' --no-pager -o cat |
+  awk '/oom-kill|Out of memory|Killed process/ {n++} END {print "Kernel OOM messages:", n+0}'
+docker ps -aq --filter label=com.docker.swarm.service.name=dokploy |
+  xargs -r docker inspect --format 'OOMKilled={{.State.OOMKilled}} ExitCode={{.State.ExitCode}} Started={{.State.StartedAt}} Finished={{.State.FinishedAt}}'
+```
+
+A startup log containing `Cancelled 1 deployments` is Dokploy's startup cleanup,
+not proof of a deployment timeout. Correlate container start/finish times and
+kernel OOM messages with the failed build. `OOMKilled=false` for Dokploy does not
+rule out a different process being killed or host-wide memory pressure. Journal
+permissions or missing history can also prevent the OOM count from being useful.
+
+If swap is absent and memory pressure is confirmed, adding swap can prevent
+abrupt memory exhaustion, but it consumes disk space and can make builds slower.
+Approve server configuration changes separately; the repository changes do not
+create swap, restart services, or change server resource limits. If builds still
+exceed available memory, move image compilation to the MacBook runner and use a
+private image-transfer or private-registry workflow.
+
 ## Gitea Actions secrets
 
 Add the following repository Actions secrets in Gitea. Use the HTTPS origin of