fix(desktop): give the SSH readiness probe room for high-RTT links#7815

test(ssh): distinguish launch and stop in readiness fixture

test(ssh): cover slow tunnel readiness on connect and reuse

Merge remote-tracking branch 'origin/main' into batch/ssh-relay-remote-03/7815

fix(ssh): bound stale tunnel reuse checks

test(ssh): remove flaky latency integration test

test(ssh): advance readiness probes under test clock

test(ssh): remove duplicate Deferred import

fix(ssh): preserve healthy tunnels on high-latency links

fix(desktop): decouple the tunnel probe timeout from the remote loop's deadline

fix(desktop): give the SSH readiness probe room for high-RTT links