fix(installer): resolve disko evaluation crash and infinite loops

- Fix disko-config.nix signature by adding '...' to handle unexpected CLI arguments.
- Update disko mode to 'destroy,format,mount' for the modern API and to avoid deprecation warnings.
- Fix infinite loops in 'configure_impermanence' and 'confirm_form_factor' caused by misinterpreting 'No' (rc=1) as an abort.

installer/disko-config.nix

@@ -19,6 +19,7 @@
 # function arguments are the right shape.
 { mainDrive
 , extraDrives ? []
+, ...
 }:
 
 let