fix(eme): destructure :timer.send_interval return, silence dialyzer

EmeLive.mount/3 dropped the {:ok, tref()} return from send_interval
on the floor. Elixir 1.19 + :unmatched_returns dialyzer flag catches
the discarded tuple; the if/else with explicit :ok arms keeps both
branches typed as :ok.

lib/microwaveprop_web/live/eme_live.ex

@@ -39,7 +39,10 @@ defmodule MicrowavepropWeb.EmeLive do
   @impl true
   def mount(_params, _session, socket) do
     if connected?(socket) do
-      :timer.send_interval(@tick_ms, self(), :tick)
+      {:ok, _tref} = :timer.send_interval(@tick_ms, self(), :tick)
+      :ok
+    else
+      :ok
     end
 
     {:ok,