Survey the machine, and say what an install would do to it

The first two pieces of the installer, and deliberately the two that change
nothing: what this machine is, and what would happen to it.

The survey is the floor under every later choice -- a component can only
offer a container shape if Docker answers for this user, or a host shape on
a systemd machine with what that shape needs. It reports what it could not
establish as unknown rather than guessing: an unprivileged probe of port 25
means "I may not bind this", not "something is listening", and reporting
the first as the second is a lie an operator would act on.

The plan is one list, and it will have three readers: --dry-run prints it,
the interface will show it before anything happens, and apply will walk it.
What you are shown is what runs.

Tested on a fresh Debian 13 in qemu, which has neither Docker nor Node and
so exercises every unavailable shape: 23 checks, including that nothing was
created by any of it. The lab that machine runs in is in e2e/vm.

e2e/vm/run.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+# SPDX-FileCopyrightText: 2026 Coffey Labs
+# SPDX-License-Identifier: AGPL-3.0-or-later
+#
+# Build the installer, copy it into the lab machine, and run a case there.
+#
+#   e2e/vm/run.sh e2e/cases/containers.sh     rewind, then run that case
+#   KEEP=1 e2e/vm/run.sh e2e/cases/hosts.sh   run it on the machine as it is
+#
+# The rewind is the point: every case starts on an identical machine, so a
+# failure is the installer's and not the last run's leftovers.
+set -euo pipefail
+CASE="${1:?usage: run.sh e2e/cases/<case>.sh}"
+ROOT="$(cd "$(dirname "$0")/../.." && pwd)"
+LAB="${LAB:-$HOME/.cache/inbuxa-lab}"
+MEM="${MEM:-4096}"; VCPUS="${VCPUS:-2}"; SSH_PORT="${SSH_PORT:-2222}"
+DISK="$LAB/lab.qcow2"; CLEAN="$LAB/lab-clean.qcow2"; SEED="$LAB/seed.iso"
+LOG="$LAB/console.log"; PIDFILE="$LAB/qemu.pid"
+. "$(dirname "$0")/lib.sh"
+
+[ -f "$ROOT/$CASE" ] || { echo "no such case: $CASE" >&2; exit 1; }
+[ "${KEEP:-}" = 1 ] || "$(dirname "$0")/reset.sh"
+vm_running || { echo "the lab is not up -- run e2e/vm/up.sh" >&2; exit 1; }
+
+echo "==> building the installer"
+(cd "$ROOT" && GOOS=linux GOARCH=amd64 go build -o "$LAB/inbuxa" ./cmd/inbuxa)
+
+echo "==> copying it in"
+vm_scp "$LAB/inbuxa" [email protected]:/tmp/inbuxa >/dev/null
+vm_scp "$ROOT/$CASE" [email protected]:/tmp/case.sh >/dev/null
+vm_ssh 'chmod +x /tmp/inbuxa /tmp/case.sh'
+
+echo "==> running $(basename "$CASE")"
+vm_ssh 'sudo -E bash /tmp/case.sh'