Add IndexedDB-backed draft persistence for CreateTeamDialog so that
navigating away (e.g. to Dashboard to install CLI) and back preserves
all form fields: team name, members, paths, solo/launch flags, color.
- New createTeamDraftStorage service (IDB + in-memory fallback)
- New useCreateTeamDraft hook (debounced save, flush on unmount, race-safe)
- Gate useEffect for defaults/initialData on draftLoaded to prevent race
- Block submit button until draft is loaded
- Improve CLI-missing error in LaunchTeamDialog with Dashboard navigation
- Remove notification bell button from MessagesPanel
