Documentation and code quality improvements across libraries
- Add README files for jsonwt, owntracks, monopam, and srcsetter
- Fix langdetect language count (47→49) in dune-project
- Remove unused variable in crockford encode function
- Improve retention type documentation in zulip channels.mli
- Refactor conpool is_healthy to reduce nesting and improve clarity
- Document unimplemented IDNA features in punycode README
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>