Initial vault-plugin-secrets-netbox

Vault/OpenBao secrets engine that mints NetBox API tokens via
/api/users/tokens/. A single seeded admin token (config) mints short-lived,
per-user tokens (roles -> creds) whose NetBox expiry is aligned to the Vault
lease; revoke deletes the token, renew extends its expiry. config/rotate
reissues the seeded admin token. Handles NetBox 4.6 v2 tokens (Bearer
nbt_<key>.<secret>) and legacy v1. Unit tests against an httptest NetBox mock;
dual Vault/OpenBao RPMs via nfpm; tag-driven release to artifactapi.

Claude-Session: https://claude.ai/code/session_01JUoARVdmhxKQHyyyp1pxeT

packaging/nfpm.yaml

@@ -0,0 +1,35 @@
+---
+# nfpm config for the vault-plugin-secrets-netbox RPM. Rendered through
+# envsubst (see scripts/build-rpm.sh) then fed to `nfpm pkg`. Built once per
+# target server (Vault, OpenBao); PACKAGE_NAME and PACKAGE_PLUGIN_DIR vary.
+
+name: ${PACKAGE_NAME}
+version: ${PACKAGE_VERSION}
+release: ${PACKAGE_RELEASE}
+arch: ${PACKAGE_ARCH}
+platform: ${PACKAGE_PLATFORM}
+section: default
+priority: extra
+description: "${PACKAGE_DESCRIPTION}"
+
+maintainer: ${PACKAGE_MAINTAINER}
+homepage: ${PACKAGE_HOMEPAGE}
+license: ${PACKAGE_LICENSE}
+
+disable_globbing: false
+
+replaces:
+  - ${PACKAGE_NAME}
+provides:
+  - ${PACKAGE_NAME}
+
+contents:
+  - src: dist/vault-plugin-secrets-netbox
+    dst: ${PACKAGE_PLUGIN_DIR}/vault-plugin-secrets-netbox
+    file_info:
+      mode: 0755
+      owner: root
+      group: root
+
+scripts:
+  preinstall: ${PACKAGE_PREINSTALL}

packaging/scripts/preinstall.sh.tmpl

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Ensure the plugin directory exists before the binary is laid down.
+# Rendered per flavour via envsubst (see scripts/build-rpm.sh).
+mkdir -p ${PACKAGE_PLUGIN_DIR}