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/ModProbe/cramfs.conf

@@ -0,0 +1 @@
+install cramfs /bin/true

initializers/system-config/ModProbe/dccp.conf

@@ -0,0 +1 @@
+install dccp /bin/true

initializers/system-config/ModProbe/freevxfs.conf

@@ -0,0 +1 @@
+install freevxfs /bin/true

initializers/system-config/ModProbe/hfs.conf

@@ -0,0 +1 @@
+install hfs /bin/true

initializers/system-config/ModProbe/hfsplus.conf

@@ -0,0 +1 @@
+install hfsplus /bin/true

initializers/system-config/ModProbe/jffs2.conf

@@ -0,0 +1 @@
+install jffs2 /bin/true

initializers/system-config/ModProbe/rds.conf

@@ -0,0 +1 @@
+install rds /bin/true

initializers/system-config/ModProbe/sctp.conf

@@ -0,0 +1 @@
+install sctp /bin/true

initializers/system-config/ModProbe/squashfs.conf

@@ -0,0 +1 @@
+install squashfs /bin/true

initializers/system-config/ModProbe/tipc.conf

@@ -0,0 +1 @@
+install tipc /bin/true

initializers/system-config/ModProbe/udf.conf

@@ -0,0 +1 @@
+install udf /bin/true

initializers/system-config/ModProbe/usb_storage.conf

@@ -0,0 +1 @@
+install usb-storage /bin/true