chore: add maintenance scripts and update editor preference

- Add scripts/cleanup.sh for package cleanup (dry-run/apply modes)
- Add scripts/nvidia-recovery.sh for broken GUI recovery
- Update AGENTS.md with new script references
- Change default editor from vim to nvim in bashrc

Co-authored-by: Junie <junie@jetbrains.com>

config/bashrc.j2

@@ -14,7 +14,7 @@ alias k='kubectl'
 alias main='bash {{ workspace_root }}/scripts/maintenance.sh'
 
 # Environment
-export EDITOR='vim'
+export EDITOR='nvim'
 export PATH="$HOME/.local/bin:$PATH"
 
 # saTway indicators