test: pin set_widget LWW gate op_id/actor tiebreaks in both arrival orders (follow-up to #161)

[christian-byrne]

Summary

Follow-up to #161, addressing the single review item from the approve-with-comments review by benceruleanlu:

In test/set-widget-lww-gate.test.ts, the op_id tiebreak case applies the higher ID before the lower one, so this file remains green if the top-level gate compares only the counter. [...] consider adding the reverse op_id arrival order and an equal-counter/different-actor case (KA-2, FC-2, FC-7).

(Quoted from the review body; no @-mention per quiet-week contact rules.)

Test-only change. No production behavior or outcome strings change.

What changed

• Reverse op_id arrival order: applies the lower op_id first at an equal counter+actor, then the higher one, which must be applied — this kills the "compares only the counter" mutation that the original forward-order test survives.
• Equal-counter / different-actor case in both arrival orders: agent:b beats agent:a at the same counter regardless of arrival order, converging on the same stamp and projected document (KA-2, FC-2, FC-7).

Evidence

• npm test -- test/set-widget-lww-gate.test.ts — 6 passed (4 pre-existing + 2 new)
• Mutation check: temporarily reduced compareStampKeys to counter-only — the 4 original tests still pass but both new tests fail, confirming the file now kills that mutation on its own; mutation reverted
• npm test — 969 passed, 8 failed in test/check-import-graph.test.ts; reproduced identically on pristine main (8 failed / 2 passed with this change stashed), so pre-existing and unrelated to this PR
• npm run typecheck — passed
• npm run lint — 0 errors (1662 existing warnings)

[coderabbitai]

Warning

Review limit reached

Next included review available in 36 minutes.

Check out review usage here.

View limit details

Limit details: You’ve used the included review currently available. Your 129 included PR review attempts over the past 7 days set your current allowance at 1 review per hour.

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

Learn how review limits work.

Review configuration:

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Team

Run ID: 7ef17034-9158-42ef-8584-9adc96fcb539

📥 Commits

Reviewing files that changed from the base of the PR and between 84030a4 and e8975f9.

📒 Files selected for processing (1)

• test/set-widget-lww-gate.test.ts

---

_{Comment @coderabbitai help to get the list of available commands.}