- Move sprint switcher into sprint header, centered between title and actions
- Extract BacklogFilterPopover as shared component used by sprint and product backlog
- Add sort options (code/priority/status) with single-pill asc/desc toggle
- Default sprint backlog status filter to OPEN, remove "alleen niet klaar" button
- Persist collapsed state and filter popover open in localStorage
- Fix hydration flicker: defer localStorage read to useEffect with prefsLoaded gate for writes
- Increase sprint switcher text size for readability
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
