chore: reduce unnecessary tooling in the server image

[TrueFurina]

Summary

Per #659: the server Dockerfile installs make in the Go builder even though it invokes go build directly, and the runtime installs curl only for the local Docker Compose health check.

Changes

• docker/server.Dockerfile:
  • removed apk add make from the Go builder (kept in the ui-builder, where make build-ui uses it)
  • removed curl from the runtime image (kept git)
• docker/docker-compose.yml:
  • replaced the curl HTTP health check with a TCP-based check (exec 3<>/dev/tcp/localhost/8080), matching the Helm chart probes — no curl needed

Verification

• Dockerfile: builder no longer installs make; runtime no longer installs curl
• Compose: health check is shell-builtin TCP, no external binary required
• Not built locally (no Docker env here); changes are minimal and follow the issue's remediation exactly