fix: centralize and nixifiy in 'zk' module

home/modules/zk/default.nix

@@ -0,0 +1,45 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+
+let
+  cfg = config.zk;
+in
+{
+  options.zk = {
+    enable = lib.mkEnableOption "zettelkasten";
+    path = lib.mkOption {
+      type = lib.types.str;
+      default = config.home.homeDirectory + "/.zk";
+      description = "Path to the zettelkasten directory";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home = {
+      sessionVariables.ZK_PATH = cfg.path;
+      packages = [
+        (pkgs.writeShellApplication {
+          name = "zk";
+          runtimeInputs = with pkgs; [ tmux ];
+          text = builtins.readFile ./scripts/zk.sh;
+        })
+
+        (pkgs.writeShellApplication {
+          name = "save-zk";
+          runtimeInputs = with pkgs; [ git ];
+          text = builtins.readFile ./scripts/save-zk.sh;
+        })
+
+        (pkgs.writeShellApplication {
+          name = "setup-zk";
+          runtimeInputs = with pkgs; [ gh ];
+          text = builtins.readFile ./scripts/setup-zk.sh;
+        })
+      ];
+    };
+  };
+}