mDNS/DNS-SD service discovery for OCaml (RFC 6762/6763)

Fix missing opam dependencies across multiple packages

- atp: add re dependency
- frontmatter: add yamlt dependency
- init: convert bytesrw, eio, bytesrw-eio from depopts to real deps
- mdns: add cstruct, fmt, cmdliner, eio_main dependencies
- owntracks: add geojson, bytesrw dependencies
- tomlt: convert eio, jsont from depopts to real deps, remove (optional) from sublibraries

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

+8
+4
dune-project
··· 20 (depends 21 (ocaml (>= 4.08)) 22 (eio (>= 1.0)) 23 (dns (>= 9.0)) 24 (ipaddr (>= 5.0)) 25 (domain-name (>= 0.4)) 26 (alcotest :with-test) 27 (crowbar :with-test)))
··· 20 (depends 21 (ocaml (>= 4.08)) 22 (eio (>= 1.0)) 23 + eio_main 24 (dns (>= 9.0)) 25 (ipaddr (>= 5.0)) 26 (domain-name (>= 0.4)) 27 + cstruct 28 + fmt 29 + (cmdliner (>= 1.2)) 30 (alcotest :with-test) 31 (crowbar :with-test)))
+4
mdns.opam
··· 12 "dune" {>= "3.0"} 13 "ocaml" {>= "4.08"} 14 "eio" {>= "1.0"} 15 "dns" {>= "9.0"} 16 "ipaddr" {>= "5.0"} 17 "domain-name" {>= "0.4"} 18 "alcotest" {with-test} 19 "crowbar" {with-test} 20 "odoc" {with-doc}
··· 12 "dune" {>= "3.0"} 13 "ocaml" {>= "4.08"} 14 "eio" {>= "1.0"} 15 + "eio_main" 16 "dns" {>= "9.0"} 17 "ipaddr" {>= "5.0"} 18 "domain-name" {>= "0.4"} 19 + "cstruct" 20 + "fmt" 21 + "cmdliner" {>= "1.2"} 22 "alcotest" {with-test} 23 "crowbar" {with-test} 24 "odoc" {with-doc}