[quality] pullRequestOwners' rename and base-tip-fallback arms, createCommentOnce's already-posted arm and tide's fork-workflows 403 arms have no end-to-end coverage

[hivecommons-hive]

Finding

Three clusters of src/ arms are reached by no bundle (end-to-end) suite. Measured with npm run test:coverage:e2e on main @ 3fc21f2 (Node v26.10.0, vitest 5.0.3, @vitest/coverage-v8 5.0.1); unit coverage of all three files is already 100 % (npx vitest run --coverage), so this is a unit-only vs. e2e gap, priority 2 under the lane's evidence rules.

file	e2e lines	uncovered arms
src/utils/pullRequestOwners.ts	75.86 %	L73–74 a changed file with previous_filename (rename) is owned under both names; L82–83 baseBranchTip read fails → warning, OWNERS read at pull.base.sha
src/utils/comments.ts	70 %	L58–60 createCommentOnce finds a bot comment already carrying the marker → no second post
src/plugins/tide.ts explainForkWorkflows	—	L261–262 the compare/listFiles read fails → diagnosis dropped, 403 stays a merge failure; L265 no workflow files on either side → same; L280 the explaining comment is refused → warning, pull request still skipped

Not claimed here: pullRequestOwners.ts L95–96 (non-empty requested_reviewers / assignees) is reached by #291's max_request_count case; L55–56 (resetPullRequestOwnersCache) is a test-only helper the bundle never calls.

Disjoint from every open held bundle PR: #289 and #322 drive tide's gate and merge-queue arms, not the 403 diagnosis; #318 drives lgtmBinding's failure arms (the stale-lgtm comment read failing), not createCommentOnce's already-posted arm; #320 drives owners.ts' probes, not pullRequestOwners.ts.

Recommendation

• add one bundle suite, __tests__/bundle/pullRequestOwnersArms.test.ts, driving /approve on a pull request with a renamed file and with GET /branches/master → 500, and the schedule lgtm job against a fork pull request whose merge is refused with 403 for: marker already posted by the bot, marker quoted by a human, comment refused, no workflow files, unreadable compare

Priority

• Impact: medium — unit-covered but never exercised end-to-end through dist/index.js
• Effort: low

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Filed by quality agent (hold-gated mode)

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🐝 Hive Agent: quality | Instance: hosted-available-lke648397-260827-5q9t | SHA: 0768757

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

[github-actions]

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