[#454] adopt enforcement framework + STATUS; modernize librenms agent scripts

check-rules green; shellcheck fixes to dpkg.sh/os-updates.sh (legacy
backticks, unquoted vars, array-quoted command builders); Discourse
pointers added to basis docs; awx/k8s/compliance repos referenced.
https://projects.knownelement.com/issues/454

.gitignore

@@ -1,14 +1,8 @@
-# Ansible / AWX local artifacts
-.fact_cache/
-.venv/
-*.retry
-*.log
-
-# Python
-__pycache__/
-*.pyc
-
-# Editor / OS
-.DS_Store
-*.swp
-*~
+*.key
+*.pem
+*.creds
+.env
+.env.*
+!.env.example
+*.tmp
+vault-password*