feat(cli): nomarchy-pull / nomarchy-rebuild / nomarchy-home

Split lifecycle into three clear commands (user pick):
  nomarchy-pull     git pull (if checkout) + flake.lock update
  nomarchy-rebuild  system switch on current lock (snap + nvd)
  nomarchy-home     Home Manager switch

Full upgrade: pull && rebuild && home. Legacy sys-update / sys-rebuild /
home-update remain as wrappers. nixos-rebuild-snap uses NOMARCHY_PATH.

V0: flake check --no-build green.

modules/home/shell.nix

@@ -69,11 +69,11 @@ in
         gpl = "git pull";
         gf = "git fetch --all --prune";
 
-        # Nix — the flake/store verbs (system/home rebuilds already have the
-        # sys-update / home-update commands, so they're not re-aliased here).
+        # Nix — store/flake verbs. Lifecycle is nomarchy-pull /
+        # nomarchy-rebuild / nomarchy-home (full names on PATH, not aliases).
         ns = "nix shell"; # ns nixpkgs#ripgrep
         nr = "nix run"; # nr nixpkgs#cowsay
-        nfu = "nix flake update";
+        nfu = "nix flake update"; # prefer nomarchy-pull day-to-day
         nfc = "nix flake check";
         nsearch = "nix search nixpkgs";
         ngc = "nix-collect-garbage -d"; # user generations; sudo for system roots