fix: types (#1344)

lua/avante/file_selector.lua

@@ -238,6 +238,7 @@ end
 
 function FileSelector:mini_pick_ui(handler)
   -- luacheck: globals MiniPick
+  ---@diagnostic disable-next-line: undefined-field
   if not _G.MiniPick then
     Utils.error("mini.pick is not set up. Please install and set up mini.pick to use it as a file selector.")
     return
@@ -245,11 +246,18 @@ function FileSelector:mini_pick_ui(handler)
   local choose = function(item) handler(type(item) == "string" and { item } or item) end
   local choose_marked = function(items_marked) handler(items_marked) end
   local source = { choose = choose, choose_marked = choose_marked }
+  ---@diagnostic disable-next-line: undefined-global
   local result = MiniPick.builtin.files(nil, { source = source })
   if result == nil then handler(nil) end
 end
 
 function FileSelector:snacks_picker_ui(handler)
+  ---@diagnostic disable-next-line: undefined-field
+  if not _G.Snacks then
+    Utils.error("Snacks is not set up. Please install and set up Snacks to use it as a file selector.")
+    return
+  end
+  ---@diagnostic disable-next-line: undefined-global
   Snacks.picker.files({
     exclude = self.selected_filepaths,
     confirm = function(picker)