refactor: Remove librenms, add ansible/salt clients

- Remove all librenms references from initializers and configuration
- Keep tailscale as requested (remove netbird plans)
- Add ansible-core (already present) and salt-minion packages
- Create salt-client initializer for minion configuration
- Update roles to replace librenms-agent with salt-client
- Simplify oam initializer to only handle up2date script
- Update README to reflect new architecture and tools

Prepares infrastructure for migration to Salt configuration management
while maintaining tailscale for VPN connectivity.

💘 Generated with Crush

Assisted-by: GLM-4.6 via Crush <crush@charm.land>

initializers/oam/librenms/postfix-queues

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+#Written by Valec 2006. Steal and share.
+#Get postfix queue lengths
+
+#extend mailq /opt/observer/scripts/getmailq.sh
+
+QUEUES="incoming active deferred hold"
+
+for i in $QUEUES; do
+        COUNT=$(qshape "$i" | grep TOTAL | awk '{print $2}')
+        printf "$COUNT\n"
+done