Add gjson package providing high-performance JSON encoding/decoding
for gopher-lua with lua-cjson API compatibility. Uses goccy/go-json
as the underlying JSON engine.
Features:
- Full lua-cjson API compatibility for OpenResty migration
- Sparse array detection and handling
- Maximum nesting depth control for encode/decode
- Number precision control
- Independent configuration instances via gjson.new()
- gjson.null sentinel for JSON null values
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
