gbrainAvailable() used `execFileSync("command", ["-v", "gbrain"])`,
which fails in any environment where the `command` builtin isn't on
the spawned process's PATH (most non-interactive shells). The probe
then reported gbrain as missing even when it was installed, and
context-load silently skipped vector/list queries.
Fix: probe `gbrain --version` directly with a 500ms timeout (matching
the rest of the file's MCP_TIMEOUT_MS). Same semantics, works
everywhere execFile works.
Contributed by @jbetala7 via #1560. Closes#1559.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
