💚 Fix flaky Bash poll test

[nbsp1221]

Summary

• Make the concurrent Bash polling test follow the existing bash_poll contract by polling while the session is running or still has buffered output.
• Remove the timing assumption that the final output and process exit marker must appear in the same snapshot, without changing production behavior.

Verification

• pnpm check — formatting, linting, typechecking, 40 unit and integration tests, and the production build passed.
• Targeted concurrent polling test repeated 10 times — all 10 runs passed.
• pnpm test:e2e — not run because this test-only change does not alter the Docker Sandbox boundary or runtime behavior.

[leverframe]

Leverframe review

🟢 Review completed in 229s

• 0 findings
• 1 of 1 changed files reviewed
• Verification: 9 passed

Changes 207d1b6..9d64823 · Commit 9d64823 · Open review · View check run

[leverframe]

Leverframe review

No actionable defects found. The revised loop matches the documented polling contract and correctly drains output until the session has exited with no buffered output. Verification used the CI-declared Node 24 environment (Node v24.20.0) and exact package manager pnpm 11.23.0, with dependencies from the frozen lockfile.

Findings

No actionable defects found.

Checks

9 passed · 0 failed · 0 not run

Show 9 checks

Status	Check	Evidence
🟢 passed	pnpm install --frozen-lockfile	Installed 464 packages from pnpm-lock.yaml using pnpm 11.23.0.
🟢 passed	pnpm exec vitest run --project integration test/integration/bash-sessions.test.ts -t 'serializes concurrent polls without duplicating or losing output' --reporter=verbose	Focused changed test passed with Vitest 4.1.11.
🟢 passed	Repeated the focused changed test 20 times	All 20 consecutive runs passed.
🟢 passed	pnpm test	All 40 unit and integration tests across 11 files passed.
🟢 passed	pnpm typecheck	TypeScript 5.9.3 completed without diagnostics.
🟢 passed	pnpm format:check	All 49 checked files matched formatting.
🟢 passed	pnpm lint	Both oxlint and ESLint completed successfully.
🟢 passed	pnpm build	tsdown 0.22.14 built the Node 24 CLI successfully.
🟢 passed	git diff --check 207d1b6c8b25f95a43e767ea5ab2c98ded628209...9d64823eb45bf0f9d6fabb00d4cdc5fe7f942a9b	No whitespace errors reported.