test(plugins): cover the error and fallback branches of lgtmBinding, ownersLabel and requireMatchingLabel

[hivecommons-hive]

Test Improvement

Adds __tests__/plugins/pluginErrorPaths.test.ts (5 tests) — the only file this PR touches. Covers the five previously unexercised branches in src/plugins/{lgtmBinding,ownersLabel,requireMatchingLabel}.ts:

• lgtmOnPullRequest binds the label as lgtm by unknown and posts no target_url when the labeled payload has neither sender nor pull_request.html_url (lgtmBinding.ts:177).
• ownersLabel rejects with could not list the repository labels: … when GET /repos/:o/:r/labels returns 500 (ownersLabel.ts:70).
• requireMatchingLabel rejects with github context payload missing issue or pull request when the payload has neither (requireMatchingLabel.ts:184).
• requireMatchingLabel rejects with require-matching-label needs-kind: could not list comments: … when GET /issues/:n/comments returns 500 (requireMatchingLabel.ts:245).
• a bot comment with body: null is treated as unmarked, so nothing is deleted on the remove path (requireMatchingLabel.ts:248).

Coverage (npm run test:coverage, origin/main 187c5e3 + this commit): lgtmBinding.ts and ownersLabel.ts 100% lines/branches (were 96.29% branches and 97.14% lines); requireMatchingLabel.ts 100% lines, 98.46% branches (was 97.7% / 95.38%; only the non-Error rejection at line 167 remains). Overall lines 96.16% → 96.29%, branches 94.55% → 94.75%. Full suite 59 files green; eslint clean. No src/ or dist/ changes.

Disjoint from #173–#202: none of those PRs touch __tests__/plugins/{lgtmBinding,ownersLabel,requireMatchingLabel}.test.ts or add a file under __tests__/plugins/ other than approveErrorPaths, tide and tideMergeQueue.

Related Issue

Closes #203

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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 automatically remove the hold label once current policy no longer requires a level hold for "quality". If this is an outreach PR, a human must review it and remove the label.

[github-actions]

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