Switch to fish shell, ghostty terminal, and simplified prompt

- Replace bash with fish as default shell (all hosts)
- Replace kgx with ghostty (desktop hosts), update Super+T keybinding
- Custom two-line fish prompt: NixOS icon, username, path, hostname, ❯
- Nix-shell awareness, red ❯ on error
- Simplify fastfetch: user@host, OS, kernel, shell, terminal, uptime, memory
- Ghostty config: FiraCode Nerd Font, catppuccin-mocha, no titlebar

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/fastfetch.nix

@@ -1,4 +1,4 @@
-{ config, pkgs, ... }:
+{ config, pkgs, lib, ... }:
 {
   # Install fastfetch
   environment.systemPackages = with pkgs; [
@@ -12,34 +12,8 @@
     nerd-fonts.meslo-lg
   ];
 
-  # Configure GNOME Console to use Nerd Font
+  # Simple fastfetch config — shown on terminal start
-  programs.dconf.profiles.user.databases = [{
+  # Run `fastfetch` manually for full system info
-    settings = {
-      "org/gnome/Console" = {
-        use-system-font = false;
-        custom-font = "FiraCode Nerd Font 11";
-      };
-    };
-  }];
-
-  # Create a script for the fastfetch command
-  environment.etc."fastfetch/custom-info.sh" = {
-    text = ''
-      #!/bin/sh
-      # Color codes
-      CYAN="\033[0;36m"
-      BLUE="\033[0;34m"
-      GREEN="\033[0;32m"
-      PURPLE="\033[0;35m"
-      GRAY="\033[0;90m"
-      RESET="\033[0m"
-      
-      echo -e "''${CYAN}$(hostname)''${RESET}''${BLUE}@NixOS_Unstable''${RESET} ''${GRAY}-''${RESET} ''${GREEN}$(uname) $(uname -r)''${RESET} ''${GRAY}-''${RESET} ''${PURPLE}$(gnome-shell --version 2>/dev/null | awk '{print $1, $3}')''${RESET}"
-    '';
-    mode = "0755";
-  };
-
-  # Create the fastfetch config file
   environment.etc."fastfetch/config.jsonc".text = ''
     {
       "$schema": "https://github.com/fastfetch-cli/fastfetch/raw/dev/doc/json_schema.json",
@@ -58,87 +32,83 @@
       },
       "modules": [
         {
-          "type": "command",
+          "type": "title",
-          "text": "/etc/fastfetch/custom-info.sh"
+          "format": "{user-name}@{host-name}"
         },
-        {
+        "separator",
-          "type": "colors",
+        "os",
-          "symbol": "circle"
+        "kernel",
-        }
+        "shell",
+        "terminal",
+        "uptime",
+        "memory"
       ]
     }
   '';
 
-  # Set up bash with fastfetch and a nice prompt
+  # Fish prompt and terminal startup
-  programs.bash.promptInit = ''
+  programs.fish.interactiveShellInit = ''
-    # Simple colored prompt without backgrounds
-    # Foreground colors
-    FG_ORANGE="\001$(echo -e '\033[38;5;208m')\002"
-    FG_GREEN="\001$(echo -e '\033[38;5;35m')\002"
-    FG_CYAN="\001$(echo -e '\033[38;5;37m')\002"
-    FG_BLUE="\001$(echo -e '\033[38;5;33m')\002"
-    FG_PURPLE="\001$(echo -e '\033[38;5;98m')\002"
-    FG_YELLOW="\001$(echo -e '\033[38;5;220m')\002"
-    FG_GRAY="\001$(echo -e '\033[38;5;245m')\002"
-    RESET="\001$(echo -e '\033[0m')\002"
-    
-    # Function to build path with colored segments
-    build_path_prompt() {
-      local output=""
-      
-      # Check if in nix-shell and show indicator
-      if [ -n "''${IN_NIX_SHELL}" ]; then
-        output+="''${FG_YELLOW}[nix-shell]''${RESET} "
-      fi
-      
-      # Username in orange
-      output+="''${FG_ORANGE}\u''${RESET} "
-      
-      # Path segments
-      local path="''${PWD/#$HOME/\~}"
-      
-      # If we're in home directory, just show ~
-      if [ "$path" = "~" ]; then
-        output+="''${FG_GREEN}~''${RESET}"
-        echo -n "$output"
-        return
-      fi
-      
-      local IFS='/'
-      local parts=($path)
-      local colors=("''${FG_GREEN}" "''${FG_CYAN}" "''${FG_BLUE}")
-      local i=0
-      
-      for part in "''${parts[@]}"; do
-        if [ -n "$part" ]; then
-          local color_idx=$((i % 3))
-          if [ $i -gt 0 ]; then
-            output+="''${FG_GRAY}/''${RESET}"
-          fi
-          output+="''${colors[$color_idx]}$part''${RESET}"
-          ((i++))
-        fi
-      done
-      
-      echo -n "$output"
-    }
-    
-    # Function to get git branch
-    parse_git_branch() {
-      local branch=$(git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/')
-      if [ -n "$branch" ]; then
-        echo -n " ''${FG_PURPLE} $branch''${RESET}"
-      fi
-    }
-    
-    # Set prompt command to rebuild on each prompt
-    PROMPT_COMMAND='PS1="$(build_path_prompt)$(parse_git_branch) ''${FG_PURPLE}❯''${RESET} "'
-  '';
-
-  programs.bash.interactiveShellInit = ''
     # Run fastfetch on terminal start
-    if [[ $- == *i* ]]; then
+    fastfetch --config /etc/fastfetch/config.jsonc
-      ${pkgs.fastfetch}/bin/fastfetch --config /etc/fastfetch/config.jsonc
+
-    fi
+    # Custom prompt
+    function fish_prompt
+      set -l last_status $status
+
+      # Nix-shell indicator
+      if set -q IN_NIX_SHELL
+        set_color yellow
+        printf '[nix-shell] '
+        set_color normal
+      end
+
+      # Line 1:  username ~ hostname
+      set_color green
+      printf ' '
+      set_color yellow
+      printf '%s' $USER
+      set_color normal
+      printf ' '
+
+      # Path with colored segments
+      set -l gitdir (command git rev-parse --show-toplevel 2>/dev/null)
+      set -l realhome (string escape --style=regex -- $HOME)
+      set -l path (string replace -r "^$realhome" '~' $PWD)
+      set -l parts (string split '/' $path)
+      set -l colors green cyan blue
+
+      for i in (seq (count $parts))
+        set -l part $parts[$i]
+        if test -n "$part"
+          if test $i -gt 1
+            set_color brblack
+            printf '/'
+          end
+          set -l cidx (math '(' $i - 1 ')' '%' 3 + 1)
+          set_color $colors[$cidx]
+          printf '%s' $part
+        end
+      end
+
+      # Hostname
+      set_color brblack
+      printf ' '
+      set_color magenta
+      printf '%s' (hostname)
+      set_color normal
+      printf '\n'
+
+      # Line 2: ❯
+      if test $last_status -ne 0
+        set_color red
+      else
+        set_color magenta
+      end
+      printf '❯ '
+      set_color normal
+    end
+
+    # Disable the default right prompt
+    function fish_right_prompt; end
   '';
 }

common.nix

@@ -69,7 +69,11 @@
   networking.networkmanager.enable = true;
   networking.nameservers = [ "1.1.1.1" "9.9.9.9" ];
 
-  # Shell aliases
+  # Fish shell
+  programs.fish.enable = true;
+  users.defaultUserShell = pkgs.fish;
+
+  # Shell aliases (work in both bash and fish)
   environment.shellAliases = {
     update = "sudo nixos-rebuild switch --flake github:ediblerope/nixos-config";
     clean = "sudo nix-collect-garbage -d";

home-manager/fred.nix

@@ -14,6 +14,17 @@
     { allowUnfree = true; }
   '';
   
+  # Ghostty config
+  home.file.".config/ghostty/config".text = ''
+    font-family = FiraCode Nerd Font
+    font-size = 11
+    theme = dark:catppuccin-mocha,light:catppuccin-latte
+    window-padding-x = 10
+    window-padding-y = 10
+    confirm-close-surface = false
+    gtk-titlebar = false
+  '';
+
   # Import gnome home manager config
   imports = [ ./gnome-hm.nix ];
 }

home-manager/gnome-hm.nix

@@ -57,7 +57,7 @@
       
       "org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom0" = {
         name = "Terminal";
-        command = "kgx";
+        command = "ghostty";
         binding = "<Super>t";
       };
       

settings/gnome.nix

@@ -8,8 +8,9 @@
     services.displayManager.gdm.wayland = true;
     boot.plymouth.enable = false;
     
-    # Add extensions and packages
+    # Add extensions, packages, and terminal
     environment.systemPackages = with pkgs; [
+      ghostty
       gnomeExtensions.blur-my-shell
       gnomeExtensions.just-perfection
       gnomeExtensions.appindicator