- Remove global experiments and plugins routes; redirect to study-scoped
pages
- Update sidebar navigation to separate platform-level and study-level
items
- Add study filter to dashboard and stats queries
- Refactor participants, trials, analytics pages to use new header and
breadcrumbs
- Update documentation for new route architecture and migration guide
- Remove duplicate experiment creation route
- Upgrade Next.js to 15.5.4 in package.json and bun.lock
