switch default shell to zsh and adopt catppuccin mocha

modules/darwin/home/default.nix

@@ -4,26 +4,49 @@
   lib,
   ...
 }:
+let
+  globalEnvironmentSecretNames = [
+    "ANTHROPIC_API_KEY"
+    "BRAVE_SEARCH_API_KEY"
+    "CROF_API_KEY"
+    "EXA_API_KEY"
+    "FAL_API_KEY"
+    "FIRECRAWL_API_KEY"
+    "GROQ_API_KEY"
+    "KIMI_API_KEY"
+    "MOONSHOT_API_KEY"
+    "OPENAI_API_KEY"
+    "OPENROUTER_API_KEY"
+    "ZAI_API_KEY"
+  ];
+in
 {
   # Import shared cross-platform home configuration
   imports = [
     ../../home/base.nix
     ../../home/shell/nushell.nix
+    ../../home/shell/zsh.nix
     ./programs/aerospace
     ./programs/kitty.nix
   ];
 
-  # Darwin-specific secrets configuration.
-  # Materialize the whole encrypted env map once, then let Nushell load it.
+  # Decrypt each global environment variable to a separate runtime file.
+  # Zsh and Nushell load the files without evaluating shell source text.
   rsydn.secrets = {
     enable = lib.mkDefault true;
     defaultSopsFile = ../../../secrets/global-env.sops.yaml;
-    secrets = {
-      "global-env" = {
-        format = "yaml";
-        key = "";
-        path = "${config.xdg.configHome}/secrets/global-env.yaml";
-      };
-    };
+    secrets = lib.genAttrs globalEnvironmentSecretNames (name: {
+      format = "yaml";
+      key = name;
+      path = "${config.xdg.configHome}/secrets/global-env/${name}";
+    });
   };
+
+  home.activation.ensureGlobalEnvironmentSecretDir =
+    lib.hm.dag.entryBetween [ "sops-nix" ] [ "writeBoundary" ]
+      ''
+        rm -f "${config.xdg.configHome}/secrets/global-env.yaml"
+        mkdir -p "${config.xdg.configHome}/secrets/global-env"
+        chmod 700 "${config.xdg.configHome}/secrets/global-env"
+      '';
 }

modules/darwin/home/programs/kitty.nix

@@ -4,34 +4,49 @@
     enable = true;
 
     settings = {
+      # JetBrainsMono Nerd Font renders the Starship powerline icons.
+      font_family = "JetBrainsMono Nerd Font";
+      font_size = 13.0;
+
       background_opacity = "0.9";
       confirm_os_window_close = 0;
       enabled_layouts = "splits,stack";
 
-      # Gruvbox colors
-      background = "#282828";
-      foreground = "#ebdbb2";
-      cursor = "#ebdbb2";
-      cursor_text_color = "#282828";
-      selection_background = "#ebdbb2";
-      selection_foreground = "#282828";
+      # Catppuccin Mocha colors (catppuccin/kitty themes/mocha.conf)
+      background = "#1e1e2e";
+      foreground = "#cdd6f4";
+      cursor = "#f5e0dc";
+      cursor_text_color = "#1e1e2e";
+      selection_background = "#f5e0dc";
+      selection_foreground = "#1e1e2e";
 
-      color0 = "#282828";
-      color1 = "#cc241d";
-      color2 = "#98971a";
-      color3 = "#d79921";
-      color4 = "#458588";
-      color5 = "#b16286";
-      color6 = "#689d6a";
-      color7 = "#a89984";
-      color8 = "#928374";
-      color9 = "#fb4934";
-      color10 = "#b8bb26";
-      color11 = "#fabd2f";
-      color12 = "#83a598";
-      color13 = "#d3869b";
-      color14 = "#8ec07c";
-      color15 = "#ebdbb2";
+      # Kitty window border colors
+      active_border_color = "#b4befe";
+      inactive_border_color = "#6c7086";
+
+      # Tab bar colors
+      active_tab_foreground = "#11111b";
+      active_tab_background = "#cba6f7";
+      inactive_tab_foreground = "#cdd6f4";
+      inactive_tab_background = "#181825";
+      tab_bar_background = "#11111b";
+
+      color0 = "#45475a";
+      color1 = "#f38ba8";
+      color2 = "#a6e3a1";
+      color3 = "#f9e2af";
+      color4 = "#89b4fa";
+      color5 = "#f5c2e7";
+      color6 = "#94e2d5";
+      color7 = "#bac2de";
+      color8 = "#585b70";
+      color9 = "#f38ba8";
+      color10 = "#a6e3a1";
+      color11 = "#f9e2af";
+      color12 = "#89b4fa";
+      color13 = "#f5c2e7";
+      color14 = "#94e2d5";
+      color15 = "#a6adc8";
     };
 
     keybindings = {

modules/darwin/homebrew.nix

@@ -45,7 +45,7 @@ in
       default = [
         "bitwarden"
         "brave-browser"
-        "font-jetbrains-mono"
+        "font-jetbrains-mono-nerd-font"
         "pgadmin4"
         "spotify"
         "vesktop"

modules/darwin/system.nix

@@ -54,8 +54,8 @@
 
   users.users.${user} = {
     home = lib.mkDefault "/Users/${user}";
-    # Use the Home Manager nushell which has proper config setup
-    shell = "/etc/profiles/per-user/${user}/bin/nu";
+    # Use the macOS system Zsh as the login shell. Nushell remains available as `nu`.
+    shell = "/bin/zsh";
   };
 
   system = {