CRITICAL PERFORMANCE FIX: Database connection optimization - Increased SQLAlchemy connection pool from 5 to 20 - Added connection recycling (5 min TTL) - Made SupabaseAuth singleton to reuse connections - Changed audit logging from commit() to flush() to batch writes - Added comprehensive performance fix documentation See PERFORMANCE_FIX.md for CRITICAL step: Must update DATABASE_URL to use Supabase connection pooler (port 6543)
