Defer need-check-nil and clean up stale suppressions

emmylua deserialises an unknown diagnostic code to a catch all that
matches no checker, so every `invisible`, `nil-check` and
`global-element` suppression was silently doing nothing. Renamed to the
emmylua codes. `name-style-check` has no equivalent and is dropped, it
was already disabled under luals.

The `get_tile` suppressions referenced an api typedef bug from 2024
which no longer reproduces.

need-check-nil is deferred rather than disabled on merit: a third of the
407 findings come from MapPosition and BoundingBox being aliased as
`struct|[double, double]`, so every `entity.position.x` reads as
possibly nil. The rest need per site knowledge of runtime invariants.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

exp_commands/module/commands/sudo.lua

@@ -19,7 +19,7 @@ Commands.new("_sudo", { "exp-commands_sudo.description" })
         --- @cast command ExpCommand
         --- @cast parameter string
 
-        --- @diagnostic disable-next-line: invisible
+        --- @diagnostic disable-next-line: access-invisible
         return Commands._event_handler{
             name = command.name,
             tick = game.tick,