ecosystem: add Inutile-Roughtime servers (FR, ES, UK, US)

[TheHuman00]

Adds four roughtime servers to the ecosystem (France, Spain,
United Kingdom, United States), all running on port 2002 with Ed25519
keys. More info at https://inutile.pro/roughtime

(I'm using this repo to run my servers, you're credited on the site!)

[tannerryan]

Thanks for raising! I added your commit and merged via #9. Since you are adding multiple servers, I introduced roughtime.SampleByOperator to ensure a single operator cannot have substantial influence on the median return when querying an ecosystem.

During sampling, if a Roughtime operator has multiple servers (dictated by unique domains), only one candidate will be used for sampling. Example:

~> roughtime-client -servers ecosystem.json
NAME                            ADDRESS                                    VERSION    MIDPOINT              RADIUS    RTT     DRIFT     STATUS
time.teax.dev                   udp://time.teax.dev:2002                   draft-12   2026-07-05T15:48:21Z  ±3s       150ms   -255ms    in-sync
Cloudflare-Roughtime-2          udp://roughtime.cloudflare.com:2003        draft-11   2026-07-05T15:48:21Z  ±1s       13ms    -358ms    in-sync
TimeNL-Roughtime                udp://rough.time.nl:2002                   draft-12   2026-07-05T15:48:21Z  ±3s       123ms   -448ms    in-sync
roughtime.sturdystatistics.com  udp://roughtime.sturdystatistics.com:2002  draft-12   2026-07-05T15:48:21Z  ±10s      165ms   -617ms    in-sync
Inutile-Roughtime-FR            udp://fr.ntp.inutile.pro:2002              draft-12   2026-07-05T15:48:22Z  ±3s       204ms   -105ms    in-sync

5/5 servers responded
Consensus drift:    -358ms (median of 5 samples)
Corrected local:    2026-07-05T15:48:22Z (now + median drift)
Drift spread:       512ms (min=-617ms, max=-105ms)
Chain:              ok (10 links verified)

Thanks again for contributing!