misc scripts: add support for arm64

misc/api.func

@@ -196,7 +196,7 @@ explain_exit_code() {
   103) echo "Validation: Shell is not Bash" ;;
   104) echo "Validation: Not running as root (or invoked via sudo)" ;;
   105) echo "Validation: Proxmox VE version not supported" ;;
-  106) echo "Validation: Architecture not supported (ARM / PiMox)" ;;
+  106) echo "Validation: Unsupported architecture (requires amd64 or arm64)" ;;
   107) echo "Validation: Kernel key parameters unreadable" ;;
   108) echo "Validation: Kernel key limits exceeded" ;;
   109) echo "Proxmox: No available container ID after max attempts" ;;