adopt neovim 0.12 native editing features

init.lua

@@ -4,6 +4,7 @@ vim.g.maplocalleader = ' '
 
 -- Load basic settings, keymaps, autocmds (kept minimal for now)
 require('settings')
+require('completion')
 require('netrw-config')
 require('keymaps')
 require('autocmds')
@@ -29,3 +30,8 @@ require('lazy').setup({
     enabled = false,
   },
 })
+
+-- Load optional native packages after lazy.nvim has finalized runtimepath.
+if vim.fn.has('nvim-0.12') == 1 then
+  vim.cmd.packadd('nvim.undotree')
+end