Add roughtime.alastyr.com to ecosystem.json

[srknk]

Adds roughtime.alastyr.com, a public Roughtime server in İzmir, Türkiye, operated by Alastyr Telekomünikasyon A.Ş.

Endpoint: roughtime.alastyr.com:2002 (UDP, IPv4 5.2.80.90 and IPv6 2a06:ad40:0:1::90)

Root public key (Ed25519): /2Al59PlwUTJHas/VS+FN6BhO9ify/wIjoH2Ezv4V7w=

The key is published by the operator on:

• https://ntp.alastyr.com/en/roughtime.html (technical details section)
• https://ntp.alastyr.com/roughtime.json (server list in the draft's format, application/roughtime-server+json)

Server:

• Software: roughtimed, draft-ietf-ntp-roughtime-19, wire version 0x8000000c.
• Transport: UDP only for now; roughtimed does not support TCP yet.
• Time source: its own GNSS receiver (dual-band, GPS/GLONASS/Galileo/BeiDou), with the PPS timestamped in hardware (stratum 1). It does not take time from other NTP servers, so it adds an independent time source.
• RADI: derived from the kernel's maxerror. It is 1 s while synchronised and grows if synchronisation is lost.
• Keys: the long-term key is kept offline and the online key is delegated for one year.

Tests performed with this branch:

• roughtime-client -servers ecosystem.json -all -two-pass: 40/40 probes responded, Chain: ok (40 links verified), including this server (±1s, in-sync).
• roughtime-stamp stamp and verify round trip against lists that include this server.
• Wrong-key requests and requests shorter than 1024 bytes get no reply, as expected.

Contact: hostmaster@alastyr.com