fix: cancel visual/operator-pending mode instead of closing buffer

Problem: when close() is triggered from visual or operator-pending
mode (e.g. pressing q after d in an oil buffer), the buffer closes
instead of canceling the pending operation. This happens because
keymaps without an explicit mode default to "" which covers normal,
visual, select, and operator-pending modes.

Solution: check the current mode at the top of close() and send
<Esc> to cancel the mode instead of proceeding with the close. The
check covers all visual modes (v, V, CTRL-V), select modes (s, S,
CTRL-S), and operator-pending submodes (no, nov, noV, noCTRL-V).

Based on: stevearc/oil.nvim#495

lua/oil/init.lua

@@ -410,6 +410,11 @@ end
 ---@param opts? oil.CloseOpts
 M.close = function(opts)
   opts = opts or {}
+  local mode = vim.api.nvim_get_mode().mode
+  if mode:match("^[vVsS\22\19]") or mode:match("^no") then
+    vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes("<Esc>", true, true, true), "n", false)
+    return
+  end
   -- If we're in a floating oil window, close it and try to restore focus to the original window
   if vim.w.is_oil_win then
     local original_winid = vim.w.oil_original_win