No advisory deterministic step: v2 gates every deterministic step on exit code, so repair-before-failure flows all re-invent '|| true'

[khaliqgant]

Context

v2 gates every deterministic step on exit code with no opt-out. v1 had failOnError: false, and it existed for one dominant pattern: run a check, let it be red, and hand its output to the agent built to answer it. That pattern — repair before failure — is the whole shape of a validated implementation flow, and in v2 every author has to re-invent a workaround for it.

Found while porting AgentWorkforce/relay's 80-to-100 validation workflows to v2. The repo's own v1-to-v2 bridge documents the workaround in flows/spec-builder.ts:

| v1                   | v2                    |
| `failOnError: false` | `<command> || true`   |

with this comment, which is the tell:

The group braces are load-bearing: || cannot begin a line, so appending "\n|| true" to a multi-line command is a shell syntax error rather than a fallback.

flows/diagnose/orchestration.spec.ts carries the same workaround under the name advisoryGate.

Why || true is not good enough

It discards the exit code. A later gate then has nothing to read, so the flow has to re-run the command to learn what happened, or the author builds an evidence journal outside the kernel. Authoring the relay native-delivery campaign I ended up writing exactly that: a recorder script that runs each command, writes {command, exitCode, verdict, tail} to disk, and always exits 0, plus a require-green gate that reads those files back. That is the kernel's job — every one of those facts is already journal-shaped.

There is a second, worse failure mode: || true is indistinguishable from success, so a flow that forgets one gate ships red work silently.

What to change

Give the deterministic step a first-class non-fatal mode. The shape that fits v2's journal-first design:

- id: run-tests
  type: deterministic
  command: npm test
  onNonZero: record     # 'fail' (default) | 'record'

record journals the exit code and output as a step outcome, marks the step complete-but-red, and lets dependents run. A later gate reads the recorded outcome — { type: 'steps_green', ids: [...] } or equivalent — rather than re-running the command.

In TypeScript, the natural form is a result object instead of a throw:

const tests = await f.run('npm test', { onNonZero: 'record' });
if (!tests.ok) await f.agent('fixer', { task: `Fix these failures:\n${tests.output}` });

Acceptance

• A deterministic step can be red without failing the run, and its exit code and output are readable by a later step from the journal.
• A gate can assert "these recorded steps were all green" without re-running them.
• || true is no longer the documented answer; the repair-before-failure pattern appears in the docs as a supported shape.

Out of scope

• Retry policy (maxIterations).
• Agent-step failure semantics.