Batch seed-discovery SSH probes into one remote command

[scuba10steve]

Summary

GroveService.resolveSeed / readFirst probe each candidate config path with a separate SshExecutor.readFile call (a fresh SSH process + cat per path). For a repo shipping no devcontainer.json/devfile, discovery pays up to 2 (devcontainer) + 4 (devfile) = 6 sequential SSH round trips before falling back to a default seed.

Suggestion

Collapse the path probing into a single remote shell command, e.g.:

for f in <paths...>; do [ -f "$f" ] && { echo "$f"; cat "$f"; break; }; done

turning ~6 handshakes into 1 and shortening the discovery step on every plant.

Notes

• Pre-existing behavior (the old per-path loop did the same); surfaced by the feat(#129): --spec flag for devcontainer/devfile precedence #164 code review, not introduced by it.
• Low urgency — correctness is fine; this is latency-only on the plant path.