Sync opam package metadata including x-maintenance-intent
and external dependency specifications.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

- Resolve merge conflict in ocaml-oci/src/checkout.ml
- Add ptime dependency to ocaml-claude-skills
- Update dune.lock
- Auto-format files with dune fmt

- 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>