Cuts detect's wall time substantially by sharing fork-exec results
between the helper that walks the JSON output and the localEngineStatus
classifier from lib/gbrain-local-status.ts.
Before: detect made 2x `command -v gbrain` calls (one in detect's
detectGbrain, one in the classifier's resolveGbrainBin) and 2x
`gbrain --version` calls. With memoization keyed on PATH, both
collapse to one fork each (~400ms saved per skill preamble).
Also adds `--fast` to the `gbrain doctor --json` call in detect so a
broken-db config (Garry's repro) doesn't burn a full 5s timeout on the
doctor's DB-connection check. The classifier still probes the DB
directly via `gbrain sources list --json` for engine reachability —
that's `gbrain_local_status`, separate from the coarse
`gbrain_doctor_ok` summary flag.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Foundation for split-engine gbrain: shared classifier used by both
bin/gstack-gbrain-detect (preamble probe) and bin/gstack-gbrain-sync.ts
(orchestrator SKIP-when-not-ok). Single source of truth.
Probes via `gbrain sources list --json` and classifies stderr against the
same patterns lib/gbrain-sources.ts:66-67 already uses ("Cannot connect to
database", "config.json"). Returns one of: ok, no-cli, missing-config,
broken-config, broken-db. Defensive default: unrecognized failures
classify as broken-config so the raw stderr can be surfaced upstream.
Cache at ~/.gstack/.gbrain-local-status-cache.json keyed on
{home, path_hash, gbrain_bin_path, gbrain_version, config_mtime, config_size}
with 60s TTL. Cache invalidates on any invariant change. --no-cache option
busts the cache for callers that just mutated state (/setup-gbrain,
/sync-gbrain after init/migration).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>