### Implemented nova spaces multi-select
##### Summary
- Renamed "All Spaces" to "Nova Spaces" - now filters to only nova content (sm_project_*)
- Added multi-select spaces support via "Select Spaces" modal
- Projects API now returns `{ nova, developer }` instead of `{ projects }`
##### Changes
- `selectedProject` → `selectedProjects[]` (array-based selection)
- New `SelectSpacesModal` component for picking multiple spaces
- Selected spaces appear at top in modal
- Search works by containerTag
- Graphs filter by selected spaces
