Add the maintainer-facing command that runs one chosen benchmark cell on
demand, so only the token budget available at that moment is spent.
runCells (bench/run-loop.ts) runs one (arm, task) cell for a batch of
trials — defaulting to five with a reporting floor of three — by driving
the existing single-cell runner and the append-only sample store rather
than reimplementing orchestration. Re-running a cell deepens it: trial
numbering continues past the highest trial the cell already holds and the
new samples append, so a cell's sample size grows across sittings without
overwriting prior runs.
bench/run.ts is the command: parseRunArgs is the pure, unit-tested
argument seam, and runBenchCommand is the live boundary that resolves host
access, resolves the scored suite against the host's self-review support,
selects the task, and drives the run loop. It is invoked via the new
bench:run npm script, run under tsx (a new devDependency) because the
harness's .js-specifier imports need a TypeScript-aware runner. The Claude
Agent SDK is now declared as an optional peerDependency — documented but
neither installed for package consumers nor pulled into CI.
Every arm runs on the driver's single fixed model; the command exposes no
per-cell model override that could break cross-arm comparability. The
default store root bench/results/ is gitignored.
