## Summary
The `homeNew` PostHog experiment has concluded. This PR graduates it by
making the new homepage (`ProjectHome`, formerly `HomeV2`) the permanent
default for all users, and removes all dead code from the old
experiment.
## Changes
- Remove `homeNew` PostHog feature flag checks and `home_new` experiment
exposure tracking from 3 files
- Rename `HomeNew/` → `ProjectHome/` directory and `HomeV2` →
`ProjectHome` export
- Delete old `Home/Home.tsx` component (shared components like
`ProjectList/` are kept — still used by org pages)
- Delete `pages/project/[ref]/building.tsx` and add a server-side
redirect from `/project/:ref/building` → `/project/:ref` to prevent 404s
during rollout (old cached JS bundles may still route to `/building`)
- Simplify `ContentWrapper` building-state logic in `ProjectLayout` —
always redirect building projects to home, always suppress building
interstitial on home page
- Always route to `/project/{ref}` after project creation (remove
`/building` path)
- Update all Observability imports from `HomeNew` → `ProjectHome`
## Self-hosted behavior change
Self-hosted Studio previously showed the old `Home` component (client
libraries + example projects) since PostHog flags don't load. This PR
changes self-hosted to show `ProjectHome` (TopSection with service
status + instance diagram, advisor, custom reports). All sections query
backend APIs that exist on self-hosted. E2E tests pass against the
self-hosted build.
## Testing
- [x] `pnpm turbo run build --filter=studio` passes
- [x] No remaining references to `homeNew`, `home_new`, or `HomeNew` in
codebase
- [x] No broken imports to deleted files
- [x] Self-hosted E2E tests pass (145 passed, 1 flaky, 4 skipped)
- [x] `/building` redirect added to both platform and self-hosted config
blocks
**Quick test:**
1. Navigate to any project homepage — should render the ProjectHome
component
2. Create a new project — should redirect to `/project/{ref}` (not
`/building`)
3. Visit a project in `COMING_UP` state on a non-home route — should
redirect to home
4. Visit `/project/{ref}/building` directly — should 302 redirect to
`/project/{ref}`
## Linear
- fixes GROWTH-671
Pamela Chia