initial implementation: encapi ENC server + CLI

Postgres-backed External Node Classifier for Puppet, replacing Cobbler.
- encapi HTTP server (chi + pgx): read/write API + two ENC document shapes
  (reshaped for the exec terminus; cobbler-wire for enc_direct_facts.rb)
- encapi-cli: classify/node/role/status CRUD + import-cobbler seeder
- pkg/client Go SDK; unit tests across all packages (DB via testcontainers)
- Dockerfile (distroless), Makefile, nfpm RPM (encapi-cli + encapi-enc wrapper),
  Woodpecker CI, docs/cutover.md

scripts/build-rpm.sh

@@ -0,0 +1,34 @@
+#!/usr/bin/env bash
+#
+# Package the (already built) encapi-cli binary into an RPM with nfpm.
+# Usage: scripts/build-rpm.sh [version]   (version defaults to $CI_COMMIT_TAG)
+#
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "${ROOT_DIR}"
+
+VERSION="${1:-${CI_COMMIT_TAG:-0.0.0-dev}}"
+VERSION="${VERSION#v}" # strip a leading v
+DIST="dist"
+
+if [ ! -f "${DIST}/encapi-cli" ]; then
+  echo "ERROR: ${DIST}/encapi-cli not found; run 'make build-cli' first" >&2
+  exit 1
+fi
+
+export PACKAGE_NAME="encapi-cli"
+export PACKAGE_VERSION="${VERSION}"
+export PACKAGE_RELEASE="1"
+export PACKAGE_ARCH="amd64"
+export PACKAGE_PLATFORM="linux"
+export PACKAGE_DESCRIPTION="CLI + Puppet ENC entrypoint for encapi (External Node Classifier)"
+export PACKAGE_MAINTAINER="Ben Vincent <ben@unkin.net>"
+export PACKAGE_HOMEPAGE="https://git.unkin.net/unkin/encapi"
+export PACKAGE_LICENSE="MIT"
+
+envsubst < packaging/nfpm.yaml > "${DIST}/nfpm.yaml"
+nfpm pkg --config "${DIST}/nfpm.yaml" --target "${DIST}" --packager rpm
+
+echo "Built:"
+ls -1 "${DIST}"/*.rpm