Two fixes for menu-bar edge cases.
- The hidden menu-bar icon is no longer a dead end — with "Show in menu bar" off, reopening Adrafinil (Finder/Spotlight) had no surface to click. It now hosts the popover in a real window, so Settings and every control stay reachable. (#11)
- Hardened the "set up again" button — it could reach for a nil app delegate; re-running setup is now always safe.