fix: make base modules enabled by default; document lazylib→lazygit

- All base/* modules now use (mkEnableOption "...") // { default = true; }
  so they activate automatically when imported — no explicit .enable = true
  required in host configs
- packages.nix: add comment documenting that lazylib does not exist in
  nixpkgs; lazygit is the correct and intended package
- zellij-ps.nix: clarify that cli.zellij-ps namespace is intentional —
  it is the home-manager module convention from m3ta-nixpkgs
- nix flake check passes (warnings are pre-existing)

home/base/shell/fish.nix

@@ -7,7 +7,8 @@
 with lib; let
   cfg = config.base.shell.fish;
 in {
-  options.base.shell.fish.enable = mkEnableOption "enable fish shell";
+  # Enabled by default — base modules are always-on.
+  options.base.shell.fish.enable = (mkEnableOption "enable fish shell") // {default = true;};
 
   config = mkIf cfg.enable {
     programs.fish = {

home/base/shell/nushell.nix

@@ -7,7 +7,8 @@
 with lib; let
   cfg = config.base.shell.nushell;
 in {
-  options.base.shell.nushell.enable = mkEnableOption "enable nushell";
+  # Enabled by default — base modules are always-on.
+  options.base.shell.nushell.enable = (mkEnableOption "enable nushell") // {default = true;};
 
   config = mkIf cfg.enable {
     programs.nushell = {

home/base/shell/starship.nix

@@ -7,7 +7,8 @@
 with lib; let
   cfg = config.base.shell.starship;
 in {
-  options.base.shell.starship.enable = mkEnableOption "enable starship prompt";
+  # Enabled by default — base modules are always-on.
+  options.base.shell.starship.enable = (mkEnableOption "enable starship prompt") // {default = true;};
 
   config = mkIf cfg.enable {
     programs.starship = {