workflow/advance and workflow/reset write on a read-only host; the Bot reply hook reaches advance #1569

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment on this issue.

Written-by: FlyBot Lead
Claimed-by: FlyBot Lead
Claim-Id: 8892d926353c4818b10923e9f64dd635
Branch: dev2/fix/p101-readonly-advance-reset
Base: ad976b4
At: 2026-10-28T07:46:46Z

Implementation: FlyBot (ours) — PR follows within 24h. Do not pick up without a pickup-ok comment.
Written-by: FlyBot Lead

What is wrong

On a read-only host, workflow/advance and workflow/reset change state and write disk without the guard the other nine write endpoints have.

• plugins/workflow/src/service.js — mutate (:774), pause (:985), resume (:1002) and the rest return { ok: false, code: 'read-only', error: 'The host is read-only' } when readOnly() is true. advance (:920-947) and reset (:1023-1076) do not: they reach storeRun() and write() (:220-227, no check), and reset's take() clears lane.active / lane.queue (:1068-1069) before writing (:1074).
• The UI path is stopped by core (core/src/host/channel.js:284-290), but the node-Bot reply hook bypasses the endpoint layer: plugins/workflow/index.js:143-152 calls service.stepResult(...) directly (:149), and stepResult calls advance() (service.js:970).

Reproduction (service level, persist: false, fake roster/spawn/dispatch)

assign  => ok: true, run status "running"
pause   => {"ok":false,"code":"read-only","error":"The host is read-only"}   # guarded
advance => ok: true        # NOT guarded: nodeStatus changes, doneCount 1
reset   => ok: true        # NOT guarded: nodeStatus undefined, active + queue cleared

readOnly means another dsh holds this team (core/src/host/hooks.js:1138, diagnostics.js:204): this plugin keeps writing workflows.json anyway, and reset kills a live run together with its queued items.

Expected

advance and reset return { ok: false, code: 'read-only', error: 'The host is read-only' } before any storeRun / write, exactly like pause(). A refused stepResult is reported once through the existing warnOnce path (service.js:964-970); nothing else changes on a writable host.

Scope

plugins/workflow/src/service.js only: one guard line at the top of advance, one at the top of reset. Tests: two cases that flip readOnly and assert the refusal plus unchanged nodeStatus / lane.queue, one of them driven through stepResult (the reply path). No behaviour change on a writable host, no new endpoint.

Docs-not-needed: the endpoint table already lists both as writes and the rule does not change.

Tests

• Red first: with the two guards reverted, the new cases fail (advance / reset answer ok: true).
• Green at the tip: the plugins/workflow suite and TZ=UTC ARCH_DOCS_BASE=<main> npm run verify.