chore: add notification when trying to change adapter (#706)

Author: niba

lua/codecompanion/strategies/chat/keymaps.lua

@@ -467,7 +467,7 @@ M.change_adapter = {
   desc = "Change the adapter",
   callback = function(chat)
     if config.display.chat.show_settings then
-      return
+      return util.notify("Adapter can't be changed when `display.chat.show_settings = true`", vim.log.levels.WARN)
     end
 
     local function select_opts(prompt, conditional)