feat: update niri config for VM, add cachyos repo script

- Update niri output config for Virtual-1 display
- Add cachyos repository installation script
- Fix btrfs device path from vda2 to vda1
- Configure sudo-rs with symbolic links
- Comment out polkit agent and swayidle spawns

greetd_niri.kdl

@@ -13,3 +13,9 @@ input {
 hotkey-overlay {
     skip-at-startup
 }
+output "Virtual-1" {
+    mode "1920x1200"
+    scale 1
+    transform "normal"
+    position x=1920 y=0
+}