M16: a way in

[youhide]

Everything written so far was for somebody implementing an init
system. Nothing was for somebody deciding whether to look at one, and the
shortest path to running it needed a Rust toolchain, a musl target, QEMU,
cpio, and a kernel you had to go and find.

Now it is:

docker run --rm --name oxinit-demo -p 8080:8080 ghcr.io/youhide/oxinit:demo

The unit set was the problem

units/ is the test suite. It contains a service that fails forever, one
that hangs, one that ignores SIGTERM, one that requires something
broken, and one that never signals readiness — all deliberate, all
necessary, and all of it reads as a crash to somebody seeing oxinit for
the first time.

demo/ is eight files that work, each showing exactly one idea:
ordering, readiness, logs, a schedule, socket activation.

curl is the demo

listen-probe learned to answer HTTP. Nothing is running on port 8080;
the request is what starts the service; the reply comes back on a
connection that was never refused.

$ curl localhost:8080
oxinit started this service because you connected.
It was not running a moment ago.

That is the shortest path from "what is socket activation" to seeing it.

The demo is tested

M13 found seven behaviours verified once and never again — the worst of
them a unit file whose comment described a test nothing ran. A README's
opening section is the same hazard with a wider blast radius.

cargo xtask test-demo runs every command the README gives a newcomer —
oxctl list, oxctl logs counter, curl localhost:8080, docker stop —
and checks that webhook is not running before the request that
starts it. It runs in CI.

Release

Fires on a pushed tag and nothing else: static binaries for both
architectures with checksums, notes generated from the merged pull
requests, and the demo image pushed to ghcr.io.

No tag is cut in this PR. A version number is a claim about
stability, and the person making that claim should be the one typing it.

Also

Two mermaid diagrams in the README — what an init system is, and the
service state machine — and a repair to CONTRIBUTING, where an earlier
edit of mine had broken a sentence and left kernel setup instructions
contradicting the ones above them.