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/Logrotate/logrotate.conf

@@ -0,0 +1,23 @@
+# see "man logrotate" for details
+
+# global options do not affect preceding include directives
+
+# rotate log files weekly
+weekly
+
+# keep 4 weeks worth of backlogs
+rotate 4
+
+# create new (empty) log files after rotating old ones
+create 0640 root utmp
+
+# use date as a suffix of the rotated file
+#dateext
+
+# uncomment this if you want your log files compressed
+#compress
+
+# packages drop log rotation information into this directory
+include /etc/logrotate.d
+
+# system-specific logs may also be configured here.