## Changed
- Increased default pool_size from 10 to 25 connections
- Increased default pool_count from 1 to 2 pools
- Faster retry for connection errors (1s base instead of 10s)
- Added explicit FCM HTTP/2 pool configuration

## Added
- Troubleshooting section in README for common errors
- Pool sizing guide with traffic level recommendations

## Fixed
- Connection errors now retry faster (1s/2s/4s vs 10s/20s/40s)

Addresses production issues:
- %Mint.HTTPError{reason: :too_many_concurrent_requests}
- %Finch.Error{reason: :request_timeout}