Product updates now have a home

Bleep That Sh*t now has a dedicated updates archive and in-app announcements for important changes.

• -The new updates archive gives product notes a stable place to live.
• -Studio can surface important announcements without interrupting every release.
• -Release notes are repo-managed, reviewed in PRs, and published to the app after deploy.

This is the first piece of the product updates workflow: a controlled way to publish release notes to the app and keep the in-app experience behind the PostHog rollout flag until we are ready.