feat: switch from lazy to vim.pack

lua/plugins/undotree.lua

@@ -1,20 +1,5 @@
-local function undo_tree_tab()
-    vim.cmd.tabnew()
-    vim.cmd.bprevious()
-    vim.cmd.UndotreeToggle()
-    vim.cmd.UndotreeFocus()
-end
+vim.cmd.packadd("nvim.undotree")
 
----@type LazyPluginSpec
-return {
-    "mbbill/undotree",
-    keys = {
-        { "<leader>uu", undo_tree_tab, mode = "n" },
-    },
-    init = function(_)
-        vim.g.undotree_WindowLayout = 2
-        vim.g.undotree_DiffCommand = "diff -u"
-        vim.g.undotree_SplitWidth = 50
-        vim.g.undotree_DiffpanelHeight = 20
-    end,
-}
+vim.keymap.set("n", "<leader>uu", function()
+    require("undotree").open({ command = "leftabove40vnew" })
+end)