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/system-config/SNMP/snmpd-physicalhost.conf

@@ -0,0 +1,46 @@
+##########################################################################
+# snmpd.conf
+# Created by CNW on 11/3/2018 via snmpconf wizard and manual post tweaks
+###########################################################################
+# SECTION: Monitor Various Aspects of the Running Host
+#
+
+# disk: Check for disk space usage of a partition.
+#   The agent can check the amount of available disk space, and make
+#   sure it is above a set limit.
+#
+load  3 3 3
+rocommunity  kn3lmgmt
+sysservices 76
+
+#syslocation Rack, Room, Building, City, Country [Lat, Lon]
+syslocation R4, Server Room, SITER, Pflugerville, United States
+syscontact  coo@turnsys.com
+
+#NTP
+extend ntp-client /usr/lib/check_mk_agent/local/ntp-client
+
+#SMTP
+extend mailq /usr/lib/check_mk_agent/local/postfix-queues
+extend postfixdetailed /usr/lib/check_mk_agent/local/postfixdetailed
+
+#OS Distribution Detection
+extend distro /usr/local/bin/distro
+extend osupdate /usr/lib/check_mk_agent/local/os-updates.sh
+
+#Hardware Detection
+extend manufacturer /usr/bin/sudo /usr/bin/cat /sys/devices/virtual/dmi/id/sys_vendor
+extend hardware /usr/bin/sudo /usr/bin/cat /sys/devices/virtual/dmi/id/product_name
+extend serial /usr/bin/sudo /usr/bin/cat /sys/devices/virtual/dmi/id/product_serial
+
+#SMART
+extend smart /usr/lib/check_mk_agent/local/smart
+
+#Temperature
+pass_persist    .1.3.6.1.4.1.9.9.13.1.3 /usr/local/bin/temper-snmp
+
+# Allow Systems Management Data Engine SNMP to connect to snmpd using SMUX
+# smuxpeer .1.3.6.1.4.1.674.10892.1
+
+# LLDP collection
+master agentx