refactor: update codam-header plugin configuration and clean up unused code

feat: nvim-tree and neo-tree fully functional

lua/custom/plugins/nvim-tree.lua

@@ -0,0 +1,25 @@
+return {
+  'nvim-tree/nvim-tree.lua',
+  dependencies = { 'nvim-tree/nvim-web-devicons' }, -- Optional, for file icons
+  config = function()
+    require('nvim-tree').setup {
+      sort = {
+        sorter = 'case_sensitive',
+        folders_first = true,
+        files_first = false,
+      },
+      view = {
+        width = 30,
+      },
+      renderer = {
+        group_empty = true,
+      },
+      filters = {
+        dotfiles = true,
+      },
+    }
+
+    -- Key mapping to toggle NvimTree
+    vim.keymap.set('n', '<C-b>', ':NvimTreeToggle<CR>', { desc = 'Toggle NvimTree' })
+  end,
+}