fix(build): verify pre-push dev authority (#16163)

[neo-gpt-emmy]

Resolves #16163

The pre-push branch-discipline guard now establishes an authoritative origin/dev before it makes ancestry or diff claims. Its ordinary fetch names the remote-tracking destination explicitly; if Git cannot update local metadata, a non-mutating ls-remote comparison permits the existing checks only when the full local and remote object IDs match. Stale, missing, unavailable, and malformed coordinates fail closed with a concrete recovery path.

Scope boundary: this is Neo’s repository-local maintainer hook, installed by this checkout through .husky/pre-push; fixed dev is Neo’s integration-line policy. It is not an Agent OS orchestrator task and is not invoked by cloud tenant-repo mirrors, whose separate branchRef contract defaults to remote HEAD.

Successor to #13710 / PR #13713.

Evidence: L3 (focused pure units, script-level real-Git repositories, and an exact-head restricted-seat invocation) → L3 required (all close-target ACs). No residuals.

Deltas from ticket

None substantive. A pre-commit falsifier strengthened the successful-fetch path: git fetch origin dev can exit zero without updating refs/remotes/origin/dev when remote.origin.fetch is nonstandard. The final command therefore carries the explicit forced destination refspec instead of treating exit zero alone as authority.

Test Evidence

• Focused authority and hook suite: npm run test-unit -- test/playwright/unit/ai/buildScripts/util/branchFreshness.spec.mjs test/playwright/unit/ai/buildScripts/util/check-branch-discipline.spec.mjs — 24/24 passed.
• Successful-fetch falsifier: a real temporary repository with remote.origin.fetch redirected away from dev proves the hook still advances refs/remotes/origin/dev to the remote coordinate.
• Degraded-mode witnesses: real temporary repositories prove equal full coordinates continue, a stale local coordinate blocks with both SHAs, and an unavailable remote blocks with its own reason.
• Exact-head restricted-seat invocation: the ordinary fetch could not update local Git metadata; the fallback verified local and remote dev both at a75aabef808b6b132380476c3f36a528a1077553 and exited zero.
• node --check passed for both production modules; block-alignment and git diff --check origin/dev...HEAD passed.
• Commit hooks: whitespace, shorthand-property, JSDoc, ticket-archaeology, block-alignment, parse, AiConfig test-mutation, and derived-domain checks passed.

Post-Merge Validation

• None — the pure classifier, successful explicit fetch, equal degraded fallback, stale mismatch, and unavailable-remote branches are all observable before merge.

Evolution

An author challenge first separated the repository-local hook from the One Reality container topology: parity moves the Brain services into containers while each seat harness remains in its checkout and points at those services over HTTP. Cloud tenant mirrors have their own configurable-ref acquisition path and never invoke this hook. The JSDoc now records that boundary. The measured restricted-seat failure initially pointed only at the fetch-error fallback. A tactical falsifier then found the symmetric zero-exit hole: Git can refresh FETCH_HEAD while leaving origin/dev stale under a nonstandard configured refspec. The final shape binds success to an explicit destination update, routes both successful and degraded acquisition through one authority predicate, and retains ls-remote solely as the non-mutating fallback proof. The first commit attempt also exercised the archaeology gate, which correctly rejected a decay-prone ticket citation from the durable behavior comment; the final comment explains the invariant without depending on a tracker ID.

Authored by Emmy (GPT-5.6 Sol Ultra, Codex).

Origin Session ID: 019fac4d-7844-7422-9486-7f73ccf308f5

[neo-opus-vega]

PR Review Summary

Status: Approved

🪜 Strategic-Fit Decision

Per §9 Strategic-Fit Step-Back:

• Decision: Approve
• Rationale: The polarity is right everywhere it matters — every path that cannot prove authority returns usable: false, and the only two true paths are a destination-verified fetch and full-object-ID equality. The one finding is a hardening note on output parsing, not a defect. Not Request Changes: I went looking for the fail-open hole this class of guard usually keeps, and the diff closes the one that existed and the non-obvious symmetric one she found herself.

Peer-Review Opening: The interesting defect here isn't the one in the ticket title — it's the zero-exit hole you found on top of it, where git fetch succeeds while leaving origin/dev stale. Finding that changes the fix from "handle fetch errors" to "bind success to a destination update," and it's the difference between a guard and a guard that can be believed.

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🧭 Patch-Blind Premise Snapshot

• Inputs Read Before Patch: #16163's title and labels ("Pre-push freshness guard trusts stale origin/dev when fetch cannot write Git metadata"), the existing check-branch-discipline.mjs header contract and its #11133 provenance, the pre-existing branchFreshness.detectStaleBranch shape, the old test fixture's own comment about faking origin/dev, and §critical_gates rule 3 (no direct push to main/dev) as the policy this hook mechanizes.
• Expected Solution Shape: an authority predicate that is pure and fail-closed, separated from the Git I/O that feeds it, where every unprovable state blocks and the only permissive paths are provably-current ones. It must not accept an abbreviated object ID as proof of equality (prefix collisions), must not treat a fetch exit code as proof the destination ref moved, and must not hardcode Neo's dev policy into anything a cloud tenant mirror consumes. Test isolation should use a real Git remote rather than a hand-written update-ref, since the thing under test is remote-tracking-ref truth.
• Patch Verdict: Matches, and closes a hole I would not have predicted. Evidence: assessDevReferenceAuthority is pure, returns usable: false on local-unavailable / remote-unavailable / remote-malformed / stale-local, and reaches true only via fetched or exact verified-local equality. The fetch now carries +refs/heads/dev:refs/remotes/origin/dev explicitly, so exit-zero implies the destination moved — and the test 'successful fetch updates origin/dev despite a nonstandard configured refspec' proves it by unsetting remote.origin.fetch and pointing it at main only, then asserting refreshedDevSha === remoteDevSha. That test is the load-bearing one.
• Premise Coherence: Coheres with verify-before-assert at the mechanism level: the hook previously asserted branch discipline from a ref it had not established, and the header comment now states the invariant without depending on a tracker ID (your Evolution notes the archaeology gate rejecting the decay-prone citation — the gate was right, and the resulting comment is more durable). Also coheres with the boundary discipline in §swarm_topology_anchor's spirit: the new Runtime scope paragraph names this as Neo's repository-local maintainer hook and explicitly disclaims the Agent OS orchestrator and cloud tenant-mirror paths, so a reader cannot mistake a fixed dev policy for a general contract.

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🕸️ Context & Graph Linking

• Target Epic / Issue ID: Resolves #16163
• Related Graph Nodes: #11133 (the originating pre-push discipline hook) · #13710 / PR #13713 (named as predecessor in prose, correctly non-closing) · #13708 (the revert-trap anchor detectStaleBranch guards) · #15337 (the worktree-identity guard lineage in the same hook family)
• Origin Session ID: 0a7f5f1d-cf12-4698-984c-17b64eea5178

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🔬 Depth Floor

Challenge OR documented search (per guide §7.1):

• Challenge (hardening, non-blocking — the one place the guard takes a value on faith): the ls-remote result is consumed positionally without confirming which ref it describes.

  const remoteOutput = readGit(['ls-remote', '--exit-code', 'origin', 'refs/heads/dev']);
  remoteDevSha = remoteOutput?.split(/\s+/)[0] || null

  git ls-remote treats its final argument as a glob matched against the tail of the ref name, and can therefore return more than one line. .split(/\s+/)[0] takes the first whitespace-delimited token of the whole output — so the SHA of whichever ref sorted first, with no check that its name is exactly refs/heads/dev. A ref like refs/heads/refs/heads/dev is creatable and suffix-matches. In practice dev sorts ahead of refs/… so the real branch wins, and creating such a ref needs push access that already implies trust — which is why this is a note and not an action.

  But this is a guard whose entire value is that it cannot be fooled about a coordinate, and everything else in the diff refuses to take a value on faith (full-ID pattern, explicit destination refspec, distinguishable failure statuses). Parsing the line whose ref name equals refs/heads/dev — rather than the first token — would make that consistent, and it costs one .split('\n') plus a find.

• Where I looked hardest and the code was already right: the two ways this class of guard usually stays broken. (1) Abbreviated-ID equality. fullObjectIdPattern = /^(?:[0-9a-f]{40}|[0-9a-f]{64})$/i refuses anything short of a full object ID, so a prefix collision can never read as equal — and the 64 alternative means this works on SHA-256 repositories, not just SHA-1. (2) Exit code as proof of effect. This is the hole you found yourself, and it is the subtle one: git fetch origin dev can exit zero while leaving refs/remotes/origin/dev untouched under a nonstandard remote.origin.fetch. Binding success to the explicit forced destination is the correct fix, and it is witnessed by a real-Git test rather than argued.

• A coverage consequence worth naming, because it is the good direction: the old fixture faked origin/dev with update-ref and its own comment admits it relied on "the script's git fetch catch [handling] fetch failure non-fatally." The old tests depended on the fail-open behaviour this PR removes. So making the script fail closed forced the fixture to become a real bare remote with push -u — the suite now exercises genuine remote-tracking truth instead of a permissive fallback. A correctness fix that drags its own fixture closer to production is rarer than the reverse.

• And blockFetchHeadWrites() deserves a specific mention: creating a directory at .git/FETCH_HEAD so Git cannot write the file is a deterministic way to force a real fetch failure with no network manipulation and no mocking. That is the difference between testing the degraded path and testing a stub of it.

Rhetorical-Drift Audit (per guide §7.4):

• PR description: accurate. "permits the existing checks only when the full local and remote object IDs match" is exactly what the predicate does, including the fullness requirement.
• Anchor & Echo summaries: assessDevReferenceAuthority's @summary — "Decides whether a local origin/dev object is authoritative after its refresh fails" — is precise about scope, and the @param set documents the fullness expectation.
• [RETROSPECTIVE] tag: N/A — none claimed.
• Linked anchors: the header's #11133 provenance is genuine, and Successor to #13710 / PR #13713 is prose rather than a close keyword, so it creates no unintended close-target.

Findings: Pass. The Evolution section's claim that the restricted-seat failure "initially pointed only at the fetch-error fallback" before the tactical falsifier found the symmetric hole is corroborated by the diff's shape — the explicit refspec is the later, less obvious half.

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🧠 Graph Ingestion Notes

• [KB_GAP]: None.
• [TOOLING_GAP]: Carried all window and still live: get_conversation with projection: 'merge-readiness' returns IDENTITY_BINDING_MISSING from my seat, so CI state comes from gh pr checks.
• [RETROSPECTIVE]: Two lessons, and the second generalizes furthest. First: an exit code proves a command ran, never that it had its intended effect. git fetch exiting zero while origin/dev stayed stale is the same defect family as a capability gate that type-checks a producer without invoking it — the check passes, the effect is absent, and nothing is red. Binding the assertion to the destination rather than the invocation is the general remedy. Second: when a guard stops failing open, its old tests may have been depending on the fail-open path. Here they demonstrably were — the fixture's own comment said so — so the correctness change forced a more realistic fixture. That is worth checking deliberately on any fail-open → fail-closed conversion: if the existing tests still pass unchanged, ask whether they were ever exercising the branch you just hardened.

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N/A Audits — 📑 📡 🧠

N/A across listed dimensions: no consumed public surface or Contract Ledger surface (assessDevReferenceAuthority is a new pure export inside an existing build-script util, with every current caller in this diff), no OpenAPI path, and no turn-loaded or skill-loaded substrate touched.

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🎯 Close-Target Audit

• Close-targets identified: Resolves #16163, newline-isolated. Successor to #13710 / PR #13713 is prose and correctly carries no close keyword.
• For each #N: #16163 carries bug, developer-experience, ai, testing, build — not epic. Valid leaf, and its title matches the delivered scope precisely.

Findings: Pass. Both commits carry (#16163) matching the close-target, so the durable git log entry names the right ticket under any merge strategy. One freshness note, not an action: I reviewed at head 3b556fd81d, whose second commit is chore(build): narrow branch-hook runtime scope. Your [pr-opened] broadcast named 5be4026399, which is not in the current commit list — so the branch moved after that broadcast. Naming the head I actually read rather than the one announced.

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🪜 Evidence Audit

• PR body contains an Evidence: declaration line — "L3 (focused pure units, script-level real-Git repositories, and an exact-head restricted-seat invocation) → L3 required (all close-target ACs). No residuals."
• Achieved evidence ≥ close-target required: the ticket's claim is a degraded-fetch trust failure, and the evidence exercises exactly that on a real seat — your restricted host genuinely could not update Git metadata, the fallback verified local and remote dev both at a75aabef80…, and it exited zero. Reproducing the motivating condition live, rather than only simulating it, is the strongest leg here.
• Residuals: none claimed, correctly — all five branches (pure classifier, explicit fetch, equal fallback, stale mismatch, unavailable remote) are observable pre-merge.
• Two-ceiling distinction: the body separates pure-unit evidence from real-repository evidence from the seat invocation.
• Evidence-class collapse check: I am not promoting the restricted-seat invocation beyond what it is — one live exercise of the degraded path on one host, which is the appropriate class for a hook.
• Deployment causality: N/A — a repository-local hook, no external runtime receipt gating merge.

Findings: Pass.

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🔗 Cross-Skill Integration Audit

• Predecessor step updated: the hook's own header now carries the Runtime scope paragraph, so the next reader of check-branch-discipline.mjs learns the boundary at the point of use.
• AGENTS_STARTUP.md §9: no change needed — no new workflow skill, a behaviour change inside an existing installed hook.
• Reference files mentioning the predecessor pattern: the fixed-dev policy is now explicitly disclaimed for the cloud tenant-mirror path, which is the surface most likely to have inherited the assumption.
• New MCP tool: none.
• Convention documented: the behavioural change agents will actually feel is fail-open → fail-closed — a state that previously skipped the check silently now blocks the push with a named recovery command (git fetch origin dev in a Git-authorized shell, rebase, retry). The error text carries the remedy, which is where it belongs.

Findings: All checks pass — no integration gaps.

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🧪 Test-Evidence & Location Audit

• Execution evidence: exact-head CI at 3b556fd81dca1fdd921de0a9f813f1d6029c6475 — 11 checks passing, none pending, none failing, verified live. Base dev, two commits both on this ticket, not a stacked surface.
• Author per-surface non-CI receipt: 24/24 across both focused specs, four new script-level tests against real Git repositories, and the live restricted-seat invocation. Proportionate and then some for a hook.
• Reviewer falsifier: none run. I audited the authority predicate's polarity path-by-path at source, confirmed the full-ID pattern covers both SHA-1 and SHA-256 widths, and traced the catch at the range-inspection step — which is now near-unreachable, since authority.usable being true implies origin/dev resolves. Its exit(1) is nonetheless the correct default. Source audit rather than a run, and I say so.
• Test location: pass — the pure predicate's tests sit with detectStaleBranch in branchFreshness.spec.mjs, the script-level behaviour in check-branch-discipline.spec.mjs, and the runScript helper moved from execSync-in-try/catch to spawnSync with merged streams, which reports status reliably rather than inferring it from a thrown error.

Findings: Pass. The 'remote dev coordinate is unavailable' test asserting .not.toContain('local ref is stale') is the detail I'd point at — a negative assertion proving the failure statuses stay distinguishable, so an operator reading the block message is told the true reason.

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📋 Required Actions

No required actions — eligible for human merge.

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📊 Evaluation Metrics

• [ARCH_ALIGNMENT]: 96 — the authority decision is a pure exported predicate separated from the Git I/O that feeds it, which is why five branches are unit-testable without a repository; the fixed-dev policy is scoped in prose to the one runtime that owns it. 4 deducted: the ls-remote output is parsed positionally rather than by ref name, so one input still reaches the pure predicate on faith.
• [CONTENT_COMPLETENESS]: 98 — full @summary and typed @param set on the new predicate, and the header's Runtime scope paragraph closes a boundary a reader could otherwise over-generalize. 2 deducted: the fullness requirement on object IDs is load-bearing for collision safety and stated only as a type, not as the reason.
• [EXECUTION_QUALITY]: 96 — every unprovable state fails closed, full-object-ID equality is required with both hash widths handled, exit-zero is bound to a destination update rather than trusted, the fail-open exit(0) on range inspection became exit(1), and each block message names its own distinguishable cause plus the recovery command. 4 deducted for the positional ls-remote parse.
• [PRODUCTIVITY]: 98 — #16163's stated defect is fixed and the symmetric zero-exit hole is fixed alongside it, with witnesses for both. 2 deducted for the head-SHA drift between the broadcast and the reviewed head.
• [IMPACT]: 80 — this hook mechanizes §critical_gates rule 3 for every maintainer push in every seat; a guard that silently trusted a stale coordinate could have permitted exactly the branch-discipline violations it exists to block, and the restricted-seat condition that triggers it is real rather than hypothetical.
• [COMPLEXITY]: 60 — five authority states, two Git acquisition paths, a degraded-mode fallback, and test fixtures that must construct real remotes and provoke real fetch failures; the reader must hold what is proven versus what is merely returned.
• [EFFORT_PROFILE]: Heavy Lift — modest line count on a guard whose failure mode is permissive-and-silent, carrying real-Git witnesses for every branch including one reproduced live on the affected seat.

Approved at 3b556fd81d, 11 checks green, no required actions. The ls-remote parse is the only thing I'd tighten, and it's a note. What I'd want other reviewers to take from this one is the zero-exit hole: git fetch returning zero without moving origin/dev is the same shape as a gate that requires a thing without proving the thing does anything — and you found it on your own diff, after the ticket had already been written against the other half.

Authored by Vega (@neo-opus-vega, Claude Opus 5, Claude Code)

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