test(bundle): drive owners.ts' truncated-tree probes and the base-branch OWNERS probe's arms through dist/index.js

[hivecommons-hive]

Test Improvement

Adds __tests__/bundle/ownersProbeArms.test.ts (new file only; nothing else touched), driving /approve by an approver on a pull request through the committed dist/index.js against fakeGithub to reach the arms of src/utils/owners.ts that a complete tree listing never does:

probeOwners — the base tip's tree is truncated

• root OWNERS 200, sdk/OWNERS 404: bob approves from the root file; the probes run root-first, one at a time (GET …/contents/OWNERS?ref=basesha, GET …/contents/sdk%2FOWNERS?ref=basesha), and no git/blobs read happens
• a probe answering 500: /approve fails with error loading OWNERS files at basesha, no label or comment write

probeBranchOwners — the tide gate's probe of the base branch

• a complete tree without an OWNERS blob: the gate wants lgtm alone and the pull request merges (PUT …/pulls/1/merge), no contents/OWNERS read
• a truncated tree without an OWNERS blob + root OWNERS 200: the gate wants approved too → skipping pr #1: missing approved
• a truncated tree without an OWNERS blob + root OWNERS 404: lgtm alone, merges
• a truncated tree + root probe 500: the merge fails with error probing for a root OWNERS file at master
• a tree listing answering 500: the merge fails with error listing the tree of master, no root probe

Evidence (main @ 3fc21f2, Node v26.10.0, vitest 5.0.3, npm run test:coverage:e2e): src/utils/owners.ts e2e 66.96 → 86.61 % lines (75 → 97 of 112), 68.66 → 85.07 % branches; probeOwners 0 → hit, every probeBranchOwners arm except the no-base.ref repoHasOwners/defaultBranch path (a defensive arm GitHub payloads never take) now reached. Bundle suite 6 files / 149 tests green; npx eslint and npx tsc --noEmit clean.

Disjoint from the open hold-gated PRs: #283 (ownersAuth.test.ts, auth.ts OWNERS arms on complete trees), #286 (approveReview.test.ts), #289 (mergeGateLabels.test.ts), #291, #293, #296, #298 (ownersLabelArms.test.ts), #300, #302, #304, #306, #308, #310, #312, #314, #316, #318, #242, #244, #246 (helpers.ts, labelCommands.test.ts, bundle.test.ts), #230, #287 — none drives a truncated tree or a contents/OWNERS?ref= probe.

Related Issue

Closes #319

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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.