home: add nh + bump zen-browser

Enable the home-manager programs.nh module (installs nh, sets NH_FLAKE so
`nh home switch` finds this repo). Re-pin zen-browser to the 2026-06-28
revision to clear a stale twilight fixed-output-derivation hash mismatch.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

flake.lock

@@ -1056,11 +1056,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1781820312,
-        "narHash": "sha256-tTFfF/wIXGH9B+m8r0g23UkzkmM3jBgWnqGC4/NFzrs=",
+        "lastModified": 1782623843,
+        "narHash": "sha256-zQdTvI8jcVfblsrWafw1ykTnCVoV94ttxb5e6drwVaI=",
         "owner": "0xc000022070",
         "repo": "zen-browser-flake",
-        "rev": "f1b189bea5972ceee02628f913f2f342ce96e21e",
+        "rev": "c59e57b9c6ea4c86f9f3b7efc92db3cbd305d078",
         "type": "github"
       },
       "original": {

home/common/programs/nix.nix

@@ -9,6 +9,13 @@
   programs.nix-index.enable = true;
   programs.nix-index-database.comma.enable = true;
 
+  # `nh` — friendlier wrapper around nix/home-manager (nh os/home switch).
+  # `flake` sets NH_FLAKE so `nh home switch` finds this repo without --flake.
+  programs.nh = {
+    enable = true;
+    flake = "/home/naps62/projects/nixos-config";
+  };
+
   home.packages = with pkgs; [
     nvd # version diff between generations (used by nh)
     nix-output-monitor # readable build output (nom; used by nh)