Added workspace management to the onboarding flow with automatic organization creation and workspace validation throughout the app.
### What changed?
- Wrapped the app layout with an `EnsureWorkspace` component that redirects users without organizations to onboarding
- Enhanced the welcome page to automatically create an organization with a generated slug when users complete their name input
- Expanded the auth context to track organizations list, restoration state, and provide organization refetching capabilities
- Added utility functions for generating unique organization slugs and usernames from display names
- Implemented proper organization restoration logic that handles saved preferences and multiple organization scenarios
### 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
1. New chat messages saving to old thread (race condition)
2. Feedback modal null handling issue (boolean | null not coerced to boolean)
3. Wrong icon on Integrations tab (was Cable, now Sun)
4. Wrong icon on Graph tab (was LayoutGridIcon, now GraphIcon)
5. Missing cursor pointer on header tabs
6. Default view was "graph" instead of "list"
