#5 - Did a lot of cleanup. first thing, the refresh system was kinda broken? so i had to refactor the whole countdown logic in use-refresh.tsx to use a ref flag instead.
also figured out that messages were being fetched TWICE. like useMessages had its own refetchInterval: 5000 AND useRefresh was doing the same thing with its own interval. so now useRefresh is the single source of truth for polling and i removed the redundant one from useMessages.

also cleaned up a bunch of stuff that was just… messy:

• extracted validateSession, exportSession, and STORAGE_KEY to lib/utils.ts because they were duplicated across files
• the delete button had no confirmation dialog, now it has
• useCopyToClipboard had a timeout leak where if you copied twice fast the old timeout would still fire. fixed that with a ref
• the delete handler now reloads the page after success so it auto-creates a new mailbox

also the countdown was ticking even when there was no session (like after deleting) which made no sense so now it checks if a session exists before counting down

anyway thats pretty much it. next up i actually need to get the inbox working