chore(lint): fix shadowed local and apply formatting

Author: mhiro2

lua/peekstack/config.lua

@@ -468,7 +468,12 @@ local function validate_ui_keys(cfg)
   for name, val in pairs(keys) do
     if type(val) ~= "string" then
       notify.warn(
-        string.format("ui.keys.%s must be a string, got %s. Falling back to %s", name, type(val), tostring(defaults[name]))
+        string.format(
+          "ui.keys.%s must be a string, got %s. Falling back to %s",
+          name,
+          type(val),
+          tostring(defaults[name])
+        )
       )
       keys[name] = defaults[name]
     end

lua/peekstack/core/stack.lua

@@ -67,9 +67,9 @@ local function unindex_popup(model)
   end
 
   -- Guard against tests mutating id/winid directly.
-  for id, entry in pairs(popup_by_id) do
+  for popup_id, entry in pairs(popup_by_id) do
     if entry.popup == model then
-      popup_by_id[id] = nil
+      popup_by_id[popup_id] = nil
     end
   end
   for wid, entry in pairs(popup_by_winid) do