Revert "nixvim: add undofile, scrolloff, wrap, yank highlight, j/k optimization"

This reverts commit f8ae5e7d66.

modules/home/nixvim/keymaps.nix

@@ -19,23 +19,6 @@
   };
 in {
   programs.nixvim.keymaps = [
-    # Search
-    (mk "<Esc>" "<cmd>nohlsearch<CR>" "検索ハイライトを解除")
-
-    # Screen line movement
-    {
-      mode = "n";
-      key = "j";
-      action.__raw = "v:count == 0 and 'gj' or 'j'";
-      options = { silent = true; expr = true; desc = "下へ移動（画面行優先）"; };
-    }
-    {
-      mode = "n";
-      key = "k";
-      action.__raw = "v:count == 0 and 'gk' or 'k'";
-      options = { silent = true; expr = true; desc = "上へ移動（画面行優先）"; };
-    }
-
     # LSP
     (mkRaw "K" "vim.lsp.buf.hover" "LSPエラーのホバー表示")
     (mk "gd" "<cmd>Glance definitions<CR>" "定義へ移動")