fix(bb-app): reuse installed tarball in package smoke

[ymichael]

What was wrong

The tarball smoke installed the packed package once for SDK checks, but then launched every packaged CLI, server, and daemon through a fresh npx --package <tarball> wrapper. That put npm package resolution and subprocess startup inside each managed process's 60-second HTTP-readiness budget. Under scheduler contention the wrapper could consume nearly the entire budget before bb-app started its server child, producing the observed live-child signature from main push run 32810192666: only the bb banner and Starting server, then the outer health timeout. A scaled packed-startup harness reproduced that exact output three times: under the same 60-burner load, the wrapped path emitted Starting server at 9.582s of a 10s ceiling and timed out, while the already-installed tarball emitted it at 112ms and reached health at 1.808s. The triggering PR #2245 changed only type imports and had no runtime effect. The package-smoke job runs one Turbo task on its own runner, so there is no evidence of within-job package-shard oversubscription; transient runner contention is the reproduction condition, not the root cause.

What changed

Keep one real npx --package <tarball> -- bb-app --help invocation to verify the package's advertised npx resolution, installation, and bin-dispatch path. Separately install the packed tarball once with lifecycle scripts enabled, then execute its npm-created .bin entries directly for help/config, full-stack, CLI/plugin, standalone server, and daemon-join checks. This removes repeated npm startup from readiness budgets while preserving the real packed-install boundary and every existing assertion: server and daemon health, builtin plugins, SDK import/status, provider bridges, plugin host worker, installed-package repacking, and multi-daemon join behavior.

No timeout or retry budget changed. No server/daemon wire contract, public CLI behavior, documentation, or HOST_DAEMON_PROTOCOL_VERSION change is involved.

How you verified

• Red before the fix: the scaled packed-startup harness under 60 CPU burners produced the exact bb / Starting server timeout three times for npx --package <tarball> bb-app; direct execution of the same installed tarball passed each reversed-order run in 1.724–1.856s.
• Green after the fix: the exact final full smoke, including the retained real npx entrypoint, passed under the same 60-burner contention in 192.78s. Its unchanged plugins, host worker, bridges, full-stack, and daemon-join assertions all passed.
• Normal local smoke improved from 51.02s before to 34.44s after without changing any clock.
• pnpm exec turbo run build typecheck test --filter=bb-app --force — 14/14 tasks passed; bb-app 72/72 tests passed.
• pnpm exec turbo run smoke:tarball --filter=bb-app --force --cache-dir=.turbo/cache --output-logs=new-only — 12/12 tasks passed; real tarball smoke passed after restoring the npx boundary.
• pnpm exec prettier --check packages/bb-app/scripts/smoke-tarball.mjs and git diff --check passed.

AGENT GENERATED: by GPT-5.6-Sol