krep v2.0.0

Highlights

• Major performance improvements in search_file threading path (single-thread fast path + lower thread-pool overhead).
• Added reproducible krep vs ripgrep benchmark script: test/benchmark_krep_vs_rg.sh.
• Expanded test coverage with real multithread consistency tests and recursive directory integration tests.
• CI hardened: build + unit tests + directory integration tests on Ubuntu and macOS.
• Recursive skip fix for minified assets (.min.*).

Dataset Benchmark Command

curl -LO 'https://burntsushi.net/stuff/subtitles2016-sample.en.gz'
gzip -dk subtitles2016-sample.en.gz
make bench-rg