- Add LStatePoolInitialSize and LStatePoolMaxSize config fields
- Set pool defaults to 100 initial / 1000 max (matching MaxConcurrentCoroutines)
- Fix middleware to return 500 on coroutine init failure instead of continuing
- Pass pool config from server init to Lua engine with zero-value fallbacks
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>