feat(workflows): set heartbeat cadence explicitly on every builtin workflow

[flora131]

Stack for #1975

Merge bottom to top; each PR is based on the one below it.

	PR	Slice
top	this PR ← you are here	builtin heartbeat cadences
	#2379	terminal cleanup and restart recovery
	#2377	scheduling and queued parent delivery
bottom	#2229	authoring contract and event payload

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Now that a positive cadence actually delivers, each bundled builtin should say what it wants rather than inherit it.

open-claude-design → 0, runs quiet

It is driven by the user reviewing generated HTML turn by turn, so the parent chat is already the thing holding it to its goal. A periodic alignment steer would interrupt that review rather than inform it.

The eight autonomous builtins → 15, stated explicitly

adversarial-verification, classify-and-act, fan-out-and-synthesize, generate-and-filter, goal, loop-until-done, ralph, tournament.

These were already resolving to 15 by omission, so their behaviour does not change. Stating it keeps the per-workflow decision visible in the definition and stops a future change to the global default from silently re-cadencing a long autonomous run — which is exactly the class of run where an unnoticed cadence change matters most.

Only open-claude-design changes behaviour.

Verification

• npm run check green
• npm run test:unit: 644 files, 6,307 tests pass
• test/unit/builtin-workflow-heartbeat-cadence.test.ts pins all nine: the eight at 15, open-claude-design at 0, and asserts every builtin carries a resolved non-negative finite cadence, so neither the disable nor the default can drift unnoticed

Note for reviewers: heartbeats are top-level only — a builtin invoked as a nested ctx.workflow(...) child never heartbeats the parent chat, so these settings apply when the builtin is launched as a top-level run.

Part of #1975

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Greptile Summary

Bundled workflows now declare their heartbeat cadence explicitly: autonomous workflows retain a 15-minute cadence, while open-claude-design remains quiet during user-led design review.

Confidence Score: 5/5

No blocking failure remains.

No accepted blocking findings remain.

T-Rex Logs

What T-Rex did

• Ran the omission probe to verify that the omission path returns a successful exit and that the resolved value matches the default of 15.
• Executed the current builtin heartbeat cadence test and confirmed all tests passed (10/10).
• Identified the relevant defaulting path in packages/workflows/src/authoring/workflow.ts (lines 162–165) and noted the non-enforcing assertion referenced in the related unit test.
• Cataloged the artifacts that support verification: the temporary omission-path e2e test source, and the outputs of the omission probe and the current cadence test.

_{Ran code and verified through T-Rex}

_{Reviews (2): Last reviewed commit: "feat(workflows): set heartbeat cadence e..." | Re-trigger Greptile}