* Check all env vars for studio and list them properly in turbo.json.
* Check all env vars for design-system.
* Fix all env vars for www.
* Fix all env vars for docs.
* Add the rest of the env vars from the packages folder.
* Revert the changes in the sign-in pages.
* Remove useless files. Fix a comment.
* Fix the links in extensions page to always point to supabase.com/docs.
* Change the feature flag rewrite in studio to point to supabase.com/.flags endpoint.
* Replace NEXT_PUBLIC_VERCEL_URL with NEXT_PUBLIC_VERCEL_BRANCH_URL because it's more stable on vercel.com. Remove it from apps where it's not needed.
* Add env vars from packages. Move all passthrough env vars to env vars since they're stable (don't change between pushes).
* Revert changes of studio files.
* Minor fixes for the merge commit.
* Replace all uses of SITE_URL with LW_URL (they're the same). SITE_ORIGIN is not constructed from env vars. LW_URL is constructed from SITE_ORIGIN and launch_week string.
* Use SITE_ORIGIN when fetching the ticket-og.