Root cause: Next.js server-side rendering was making API calls without
forwarding browser cookies, causing AUTHORIZATION_ERROR during page load.
Changes:
- Updated getAdminClubs() to accept optional cookieHeader parameter
- Updated getAdminClubDetail() to accept optional cookieHeader parameter
- Modified /admin/clubs page to extract cookies via next/headers and
forward them to API calls during SSR
- Use credentials: 'omit' when manually setting Cookie header to avoid
fetch() conflicts
Result: Admin endpoints now authenticate properly during SSR, allowing
page to render club list correctly instead of showing error state.
Resolves: SSR authorization error reported in BUILD:283 regression test