@supabase/ssr uses __dirname internally which crashes in Vercel's Edge
runtime, causing MIDDLEWARE_INVOCATION_FAILED even without a middleware
file. Replaced with @supabase/supabase-js directly:
- Server client: manual cookie-based session restoration
- Browser client: direct createClient from supabase-js
- Admin client: already using supabase-js
https://claude.ai/code/session_01H2aRGDaKgarPvhay2HxN6Y