test(bundle): drive lgtmBinding's failure arms and /lgtm cancel's failed reads and writes through dist/index.js

[hivecommons-hive]

Test Improvement

Adds one file, __tests__/bundle/lgtmBindingArms.test.ts (8 tests), which runs the shipped dist/index.js against the fake GitHub API for the failure arms of src/plugins/lgtmBinding.ts and src/labels/lgtm.ts that no bundle suite reached:

• /lgtm by a member reviewer when POST /statuses/{sha} answers 500: refused with could not bind lgtm to … (not the 403 permission hint), no label applied, and the post-command sweep still runs; and the same when the refusal comment itself fails (both errors logged, run fails)
• /lgtm cancel when GET /issues/1 fails and when DELETE /issues/1/labels/lgtm is refused: run fails naming the step, head never unbound
• pull_request labeled lgtm by a human when GET /commits/{sha}/status answers 500 and 403: run fails naming the read (403 names statuses: write), nothing merged or stripped
• pull_request labeled lgtm by a bot when the stale-lgtm comment read fails: label stripped, status set pending, the comment failure is a warning, run passes
• pull_request labeled lgtm on a payload with no pull_request.head: run fails, no status written

No production code, dist/, helpers.ts, fakeGithub.ts or config changes.

Coverage (npm run test:coverage:e2e, main @ 3fc21f2)

file	before	after
src/plugins/lgtmBinding.ts	88.63 % lines	100 % lines
src/labels/lgtm.ts	88.88 % lines	97.77 % lines (39, the missing-issue-number guard, is unreachable from handleIssueComment)

Disjoint from the open bundle PRs: #289 routes only a successful prow/lgtm status read, #310 covers handlePullReq's jobs input (onPrLgtm), #246 holds helpers.ts/bundle.test.ts — none of them drive these arms.

Related Issue

Closes #317

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Filed by quality agent (hold-gated mode). Human review required.

— hive: agent=quality backend=copilot model=claude-fable-5.1 copilot=1.0.88

[hivecommons-hive]

Important

Held for human review by the hive's ACMM level gate.

This PR was opened by the "quality" agent while Hive policy required a human checkpoint for that agent. Non-outreach agents are held at ACMM L3–L5; the outreach agent is always held because it publishes project-facing communication.

Hive will keep the hold label until a human removes it. Operators can make a deliberate one-off release during an ACMM level change with release_level_holds=true, but level changes never release this hold automatically.

[github-actions]

Please add a kind label with /kind failing-test or /kind cleanup.