`_start_local_openviking_server()` spawned `openviking-server`
unconditionally. Both callers — `initialize()` and the runtime
unreachable handler — reach it from a health probe, and that probe can
time out client-side while the server is up and serving. The spawned
process then loses the data-directory lock and exits immediately with
`DataDirectoryLocked`; because the probe keeps timing out, the cycle
repeats every cooldown window (~5 min observed).
The existing 30s `_failed_refresh` cooldown paces the loop but cannot
stop it, since it expires while the underlying condition persists.
Probe the target host:port before spawning and treat an occupied port as
already-started. This guards both call sites at their single convergence
point. The probe deliberately tests only that a listener owns the port —
enough to know a second server would lose the lock — and says nothing
about that listener's health.
The parse/probe now precedes the PATH lookup, so a reachable server is
reported as running even when `openviking-server` is not on PATH.
Fixes#74846
(cherry picked from commit b49427d85fd6628eb4a7fe099e5c390c5c4cc935)
Jeff Mettel
a3f6953f1a