feat(home): add nix-index-database flake input (#317)

Wire up the nix-index-database flake to provide the comma binary with a pre-built nix-index database. Removes the manually-installed pkgs.comma in favor of the module-managed version.

Co-authored-by: Claude Haiku 4.5 <noreply@anthropic.com>

Author: stackptr

flake.lock

@@ -27,6 +27,10 @@
       url = "github:cachix/git-hooks.nix";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    nix-index-database = {
+      url = "github:nix-community/nix-index-database";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     nixos-hardware.url = "github:NixOS/nixos-hardware";
 
     # Linux

flake.nix

@@ -9,6 +9,7 @@ inputs @ {
   homebrew-core,
   homebrew-cask,
   llm-profile,
+  nix-index-database,
   zx-dev,
   disko,
   golink,
@@ -35,6 +36,7 @@ inputs @ {
     home-manager.users.${username} = {...}: {
       imports =
         [
+          nix-index-database.hmModules.nix-index
           agenix.homeManagerModules.default
           ./../modules/home
           ./../home

lib/hosts.nix

@@ -85,9 +85,13 @@ in {
     })
 
     (mkIf cfg.nix.enable {
+      programs.nix-index = {
+        enable = true;
+      };
+      programs.nix-index-database.comma.enable = true;
+
       home.packages =
         [
-          pkgs.comma
           pkgs.manix
           pkgs.nix-du
           pkgs.nix-tree