feat: libvirt setup

fix: ip assigment index
feat: default username

lnvps_db/migrations/20250328220956_fixes.sql

@@ -0,0 +1,4 @@
+-- Add migration script here
+ALTER TABLE vm_ip_assignment DROP KEY ix_vm_ip_assignment_ip;
+alter table vm_os_image
+    add column default_username varchar(50);

lnvps_db/src/model.rs

@@ -206,6 +206,7 @@ pub struct VmOsImage {
     pub release_date: DateTime<Utc>,
     /// URL location of cloud image
     pub url: String,
+    pub default_username: Option<String>,
 }
 
 impl VmOsImage {