### fix: space selector state bugs on create and delete
Two related bugs in the space selector caused by query cache key mismatches in `use-project-mutations.ts`:
1. New spaces not appearing in dropdown until refresh — wrong query cache was being invalidated after creation.
2. App stuck on deleted space instead of switching to Nova Spaces — delete handler was reading from an empty cache, so the selection never updated.
### 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
### Add user display name functionality and enhance space management with emoji support and deletion capabilities.
### What changed?
- Added support for user display names, which are now stored and displayed throughout the app
- Implemented emoji support for spaces (projects), allowing users to customize their space icons
- Created a new `AddSpaceModal` component with emoji picker for creating spaces
- Added space deletion functionality with options to move content to another space or delete everything
- Enhanced the space selector UI to show emojis and delete options
