Rust (axum) service — z3k platform template

A minimal axum HTTP service, wired for the platform:

• listens on PORT (default 8080), health checks on /health
• every push to main builds and publishes an image; the platform deploys it automatically
• env vars come from the console's Configuration tab

Edit src/main.rs, push, and watch your deployment in the console.

Note: the first CI build is slower (cold cargo cache); later builds reuse the dependency layer and are much faster.