refactor: integer functions, optimize asserts #34112

refactor(lua): add integer coercion helpers

Add vim._tointeger() and vim._ensure_integer(), including optional base
support, and switch integer-only tonumber()/assert call sites in the Lua
runtime to use them.

This also cleans up related integer parsing in LSP, health, loader, URI,
tohtml, and Treesitter code.

supported by AI

runtime/lua/vim/pack.lua

@@ -1157,7 +1157,7 @@ local function show_confirm_buf(lines, on_finish)
   --- @type integer
   local cancel_au_id
   local function on_cancel(data)
-    if tonumber(data.match) ~= win_id then
+    if vim._tointeger(data.match) ~= win_id then
       return
     end
     pcall(api.nvim_del_autocmd, cancel_au_id)