# 0.1 — Module and entrypoint (GREEN)

Phase: 0 — Foundations
Stage: GREEN

- [x] A single Go module builds one static binary with no cgo
- [x] The binary reads its configuration at startup and serves HTTP on a configurable listen address
- [x] `SIGTERM` starts a drain: the listener stops accepting new connections, in-flight requests run to completion, then the process exits `0`
- [x] A request already in flight when `SIGTERM` arrives receives its full, uncorrupted response body
- [x] A request arriving after `SIGTERM` is not accepted on a new connection
- [x] The drain has a bounded deadline; exceeding it forces exit with a non-zero code and a logged reason
- [x] The process holds no Kubernetes credentials and makes no API-server calls

The gateway sits behind ingress-nginx, which owns TLS. The gateway never terminates
TLS and never listens on 443. Graceful drain matters because in-flight requests here
are LLM generations that can legitimately run for many minutes -> killing them
mid-stream loses work a caller cannot cheaply redo.

## Verify

```bash
go test ./internal/server/... -run TestGracefulShutdown -race -v
# expected: passes — a slow in-flight request completes with a full body after SIGTERM,
# and a request issued post-SIGTERM is refused; process exit code is 0

CGO_ENABLED=0 go build ./... && go vet ./...
# expected: both succeed
```

`-race` is required, not optional. A server that starts a listener in one goroutine and
exposes its address from another is the obvious shape here, and it is racy unless the
shared state is guarded. A test that passes without `-race` proves nothing about it.