fix: reduce SSH interactive lag (GSSAPIAuthentication + TCPKeepAlive) (#1795)

* fix: reduce SSH interactive lag with GSSAPIAuthentication=no and TCPKeepAlive=no

GSSAPIAuthentication causes latency on every SSH interaction when
the server doesn't support Kerberos (i.e. always for our VMs).
TCPKeepAlive is redundant with ServerAliveInterval and can cause
retransmission issues through NAT/firewalls.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: use SSH_INTERACTIVE_OPTS for all interactive sessions

The reconnect (cmdConnect) and agent launch (cmdEnterAgent) paths
were using bare SSH with only StrictHostKeyChecking, missing all
performance flags. Now they use SSH_INTERACTIVE_OPTS which includes:

- GSSAPIAuthentication=no (skip Kerberos timeout)
- TCPKeepAlive=no (avoid NAT retransmission issues)
- ServerAliveInterval=15 (encrypted keepalives)
- Compression=yes (reduce latency on slow/distant links)
- IPQoS=lowdelay (mark packets for low-latency treatment)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: lab <6723574+louisgv@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@openrouter/spawn",
-  "version": "0.7.9",
+  "version": "0.7.10",
   "type": "module",
   "bin": {
     "spawn": "cli.js"