feat: nixvim refactor

modules/home-manager/programs/nixvim/presets/base/tree.nix

@@ -0,0 +1,32 @@
+{ lib, config, ... }:
+let
+  cfg = config.presets.base.tree;
+in
+{
+  options.presets.base.tree = {
+    enable = lib.mkEnableOption "file tree";
+  };
+
+  config = lib.mkIf cfg.enable {
+    keymaps = [
+      {
+        key = "<leader>ft";
+        action = "<cmd>:Neotree toggle<CR>";
+      }
+    ];
+    plugins = {
+      neo-tree = {
+        enable = true;
+        filesystem.filteredItems.visible = true;
+        eventHandlers = {
+          file_opened = ''
+            function()
+              require('neo-tree').close_all()
+            end
+          '';
+        };
+      };
+      which-key.registrations."<leader>f".t = "Tree";
+    };
+  };
+}