fix(fabrika): seat exit 11 in write-pattern's two writing verbs (#5355)

[usirin]

The write-pattern CLI contract already defines exit 11 for "a precondition read failed", and three of its five verbs use it. The two verbs that write files — pattern new and pattern register — did not, so a read that errored fell through to exit 1, the code this repo reserves for "the call never ran". This adds the missing seat to both verbs so a failed read is told apart from a call that never happened.

Six table rows, no code change: one Exit status row per verb, plus one Errors row per exit-11 site in the shipped verb (one for pattern new, three for pattern register), reusing the shared matrix's existing 11 PRECONDITION_UNKNOWN.

• pattern new — 11 when the target-path existence check itself fails, so existence is neither proven nor disproven (distinct from 13, which is proven).
• pattern register — 11 at each of its three precondition reads: the <dir>/index.md existence check, the <dir>/index.md read, and the <dir>/<slug>.md existence check (distinct from 15 and 12, which are proven facts).

Message wording is quoted verbatim from the shipped verbs (packages/fabrika-cli/src/pattern/{new,register}-verb.ts) — pattern <verb>: cannot check|read <path>: <reason> — nothing was written. No new exit code is minted, nothing is renumbered, exit 7 (ZERO_SCOPE) stays unseated, codes 3–6 stay deliberate gaps, and the shared matrix, the seat map, and the three verbs that already seat 11 are untouched.

Same defect and same shape as #4736 in the sibling adr contract; belongs to the #4208 collision (a failed read is not a call that never ran).

Fixes #5355

Deviations

• Scope narrowing / different shape (repair round 1) — Said: write-pattern contract: no exit 11 seat in pattern new / pattern register #5355's What the fix is
  asks for "four rows total, two per verb", and AC2/AC4 ask for the stderr row "in the group's
  existing refusal wording, naming the outcome as UNKNOWN". Did: six rows — pattern register
  gets three Errors rows, one per exit-11 site in the shipped verb — and the wording is quoted
  verbatim from packages/fabrika-cli/src/pattern/{new,register}-verb.ts (— nothing was written.),
  which carries no UNKNOWN token. Why: write-pattern contract: no exit 11 seat in pattern new / pattern register #5355 was filed before Five fabrika pattern verbs are specified and none exists #5332 shipped, so its suggested
  wording is a guess at bytes that now exist; an Errors table that does not match what the binary
  prints is the defect the round-1 review FAILed on. Disposition: no action needed — reviewer-
  directed in the review-skill: FAIL @ 04353efb verdict; the seat-level UNKNOWN semantics AC2 wants
  are carried by the Exit status rows, and no code change is implied.

[github-actions]

No preview deploy

• No preview deploy for this PR — its diff touches no deploy-relevant path, so no preview stack was minted and e2e is not applicable. _(c4f598e)

• web — Stage pr-5365 torn down.

[usirin]

review-skill: FAIL @ 04353ef — changes-requested

Reviewed-head: @ 04353ef

Verified PR #5365 against #5355's acceptance criteria + the skill-rigor checklist. Class: non-blocking (claude-plugins/fabrika/** is not in the live CONTROL_PLANE_RE; cp-classify: not-control-plane [path-clear-no-content-source]). Required namespace set for this diff: review-skill (1 file, has-skills).

The finding in one line: the four rows land, but the two Errors rows specify stderr bytes that the already-merged implementation does not emit, and pattern register's single row does not cover two of the three sites where the shipped verb actually returns 11.

The write-pattern verbs are no longer unbuilt: #5332 closed completed at 2026-08-10T20:32:58Z via PR #5356, and packages/fabrika-cli/src/pattern/ is on origin/main already seating PRECONDITION_UNKNOWN in both writing verbs. On origin/main:

Site	Shipped stderr (origin/main)
new-verb.ts:47	pattern new: cannot check <path>: <reason> — nothing was written.
register-verb.ts:60 (index existence)	pattern register: cannot check <dir>/index.md: <reason> — nothing was written.
register-verb.ts:69 (index read)	pattern register: cannot read <dir>/index.md: <reason> — nothing was written.
register-verb.ts:77 (doc existence)	pattern register: cannot check <dir>/<slug>.md: <reason> — nothing was written.

Every other row in these two Errors tables is verbatim the string the code emits (pattern new: <path> already exists — refusing to overwrite., pattern new: cannot write <path>: <reason> — whether anything landed is UNKNOWN., pattern register: <dir>/index.md is absent — …, pattern register: no doc at <dir>/<slug>.md — …). That verbatim relationship is the table's contract. The two rows this PR adds are the only ones in either table that break it.

Acceptance criteria

• [PASS] pattern new Exit status seats 11 for the existence check itself failing — contract.md:692, and the trigger text matches the shipped guard exactly (new-verb.ts:44 refuses PRECONDITION_UNKNOWN when exists(path) fails), distinct from 13.
• [FAIL] pattern new Errors row at 11 — contract.md:700 specifies pattern new: cannot determine whether <path> exists: <reason> — UNKNOWN, never "absent"; nothing written.; the shipped verb emits pattern new: cannot check <path>: <reason> — nothing was written. (new-verb.ts:47, on origin/main). The row is not the matching message for the seat it documents, and it is the only row in this table that is not the code's literal string.
• [PASS] pattern register Exit status seats 11, distinct from 15 and 12 — contract.md:816, and the "never 15 or 12, which are proven facts" clause is exactly the cp-classify exit 1 means both a proven not-§CP verdict and a failed invocation #4208 distinction the issue asked for.
• [FAIL] pattern register Errors row at 11 — contract.md:825 carries one row, pattern register: cannot read <path>: <reason> — UNKNOWN, never "absent"; nothing written. Two problems: (a) the bytes differ from the shipped string (— nothing was written., register-verb.ts:69); (b) the verb seats 11 at three sites, and the two existence probes emit cannot check … (register-verb.ts:60 and :77), which no row in the table describes. The step-2 <dir>/<slug>.md case the Exit-status row promises is therefore documented with a message the implementation never prints.
• [PASS] No new exit code minted, none renumbered — the diff adds four rows and reuses the shared matrix's existing 11 PRECONDITION_UNKNOWN (contract.md:132); no numeral in any table changed.
• [PASS] Exit 7 (ZERO_SCOPE) stays unseated and 3–6 stay deliberate gaps — the deliberate-gaps table (contract.md:165–169) is outside every diff hunk, and no verb's Exit status table seats 3–7 at head.
• [PASS] Shared exit matrix, seat map and the three verbs that already seat 11 unchanged — the four hunks are confined to lines 689/696/811/819; contract.md:132, :141 and the corpus/drift/anchor seats at :246, :391, :564 are untouched.

Skill rigor

• [FAIL] Behavioral correctness — read as the spec an implementer executes, the amended contract now instructs a reader to emit strings the shipped verbs do not, and leaves register's two cannot check … refusals undocumented. Since the code landed after write-pattern contract: no exit 11 seat in pattern new / pattern register #5355 was filed, the artifact this PR should produce is a contract that describes the built behaviour; instead it introduces a contract↔code disagreement in the exact place the issue exists to make unambiguous. Remedy is still four cells: use the shipped bytes, and give register a second row (or one cannot check|read row) covering the existence probes at register-verb.ts:60 and :77.
• [PASS] Trigger / description quality — contract.md carries no frontmatter description; write-pattern/SKILL.md and its trigger surface are outside the diff, so no trigger widened or narrowed.
• [PASS] Cross-skill conflict / shadowing — the seat is imported, not minted: pattern/codes.ts:24,36 re-exports PRECONDITION_UNKNOWN from build/codes.ts, and exit-code-alignment.ts (SHARED_SEATS) already claims PRECONDITION_UNKNOWN as a shared seat, so nothing collides with report/triage/review. Wording follows the sibling adr contract's shape (adr/contract.md:139, :381, :655).
• [PASS] Gate-invariant preservation — no §CP path in the diff, no gate skill in reach, and the change adds a refusal seat rather than relaxing one. No pipeline invariant is weakened.
• [PASS] Contract implementation ticket (ADR 0248) — in scope (the diff changes claude-plugins/fabrika/skills/write-pattern/contract.md), and satisfied in substance: the five verbs this contract specifies are built and merged (Five fabrika pattern verbs are specified and none exists #5332 closed completed via PR feat(fabrika): implement the write-pattern contract's five pattern verbs (#5332) #5356), so no unbuilt spec enters the build pool. This is also why the FAIL rows above matter — there is a live implementation for these rows to disagree with.
• [PASS] deviation-disclosure (§DEV) — the body's ## Deviations section is present and says None.; the Tier-M scan surfaces no undisclosed departure from the issue, an AC, or a governing ADR. Nothing undisclosed that this gate could see.

Read the PR head (§HEAD): all contract text under review sourced from 04353efbb1b40736efe6a80dfcb36a7f35d4d008 via the isolated review worktree; the implementation bytes were read from a freshly fetched origin/main, never a working copy.

Failing items above must be addressed before this PR can merge. The PR stays open and unmerged; #5355 stays open and assigned. Re-request review once they're satisfied.

Verdict-written: 2026-08-10T21:19:49Z

[usirin]

review-skill: PASS @ c4f598e — merge-ready

Reviewed-head: @ c4f598e

Re-gate of PR #5365 after repair round 2 (prior verdicts: FAIL @ 04353efb, FAIL @ c4f598eb). Class: non-blocking — cp-classify: not-control-plane [path-clear-no-content-source]; the single changed file claude-plugins/fabrika/skills/write-pattern/contract.md matches no branch of the live CONTROL_PLANE_RE (only claude-plugins/kampus-pipeline/** sub-paths are in the live CODEOWNERS) and the diff carries no .decisions/** file, so ADR 0164's content clause has nothing to decide. This marker binds ship-it.

Required namespace set for this diff (1 file, has-skills): review-skill — and only that. No code root, no .decisions/.patterns/root-doc path, no apps/web/src/ path, so review-code, review-doc and review-design are correctly not dispatched and emit nothing.

The head is unchanged. headRefOid is still c4f598eb634d942a476eaf9e698894afad3d2b5d (two commits: 04353efb @ 21:09:50Z, c4f598eb @ 21:26:42Z — nothing pushed since). Repair round 2 was a PR-body edit only, so the six-row diff I already validated byte-exact at this head is bit-identical, and the substance verdict below carries forward unchanged.

The round-2 blocker is fixed. The one FAIL standing at this head was deviation-disclosure: ## Deviations said None. while round 1 had made two reviewer-directed departures, and the summary above it still asserted the pre-repair state. Re-read of the live body:

• ## Deviations now carries the round-1 entry, tagged **(repair round 1)** per §DEV's append rule, in the Said / Did / Why / Disposition shape. Both departures are named: six rows instead of write-pattern contract: no exit 11 seat in pattern new / pattern register #5355's "four rows total, two per verb" (pattern register has three exit-11 sites), and the wording quoted verbatim from the shipped verbs rather than AC2/AC4's literal "naming the outcome as UNKNOWN". Disposition is stated and correct — reviewer-directed in the review-skill: FAIL @ 04353efb verdict, no code change implied, and the seat-level UNKNOWN semantics AC2 asks for are carried by the two Exit status rows.
• The two stale summary sentences are corrected and no longer contradict the diff. The body now reads "Six table rows … one Exit status row per verb, plus one Errors row per exit-11 site in the shipped verb (one for pattern new, three for pattern register)" — which is exactly the 2 + 4 = 6 added rows — and "Message wording is quoted verbatim from the shipped verbs … — nothing was written.". Grep of the live body returns zero hits for Four table rows, for the deleted never "absent" wording, and for a None. line. Nothing in the description now asserts a state the head does not hold.
• Round 2 itself introduced no new departure from write-pattern contract: no exit 11 seat in pattern new / pattern register #5355 (it changed no file in the diff), so no **(repair round 2)** entry is owed.

Acceptance criteria — re-confirmed against the same head; the diff is the same six added rows, zero removed lines, against merge base 0478bdb1.

• [PASS] AC1 — pattern new Exit status seats 11 for an incompletable existence check — contract.md:692, "the target-path existence check itself failed, so whether <path> exists is UNKNOWN — never read as absent, and never 13, which is proven". Matches the shipped control flow: new-verb.ts:46 returns PRECONDITION_UNKNOWN before the ALREADY_EXISTS branch, so 11 genuinely precedes 13.
• [PASS] AC2 — pattern new Errors row at 11 — contract.md:700, pattern new: cannot check <path>: <reason> — nothing was written. Byte-exact against the shipped literal at new-verb.ts:47 (fixed-string match, em dash included). Kind is refusal at code 11, not a usage error at 1 — the substance AC2 asks for; the literal-wording departure is disclosed in ## Deviations.
• [PASS] AC3 — pattern register Exit status seats 11 distinct from 15/12 — contract.md:816, naming both the step-1 <dir>/index.md and step-2 <dir>/<slug>.md reads and stating "never 15 or 12, which are proven facts". Matches register-verb.ts, where each PRECONDITION_UNKNOWN refusal precedes its proven-fact sibling.
• [PASS] AC4 — pattern register Errors rows at 11, one per exit-11 site, byte-exact and exactly covering — register-verb.ts:61 cannot check ${indexPath} → contract.md:825; :70 cannot read ${indexPath} → contract.md:826; :78 cannot check ${docPath} → contract.md:827. Coverage is exact in both directions: grep -n 'PRECONDITION_UNKNOWN' on the shipped register-verb.ts returns the import plus exactly those three refusal sites, and no fourth.
• [PASS] AC5 — no new exit code minted, none renumbered. Six added lines, zero removed, every row reusing the shared matrix's existing 11 PRECONDITION_UNKNOWN.
• [PASS] AC6 — exit 7 (ZERO_SCOPE) stays unseated and 3–6 stay deliberate gaps; no verb exit table gains a row in 3–7.
• [PASS] AC7 — the shared exit matrix, the group's seat map, and the three verbs that already seat 11 (corpus, drift, anchor) are untouched. The zero-removal diff reaches only the two writing verbs' Exit status and Errors tables.

Skill rigor

• [PASS] Behavioral correctness — the contract reads as a spec for an implementer and as a refusal catalogue for a caller reading stderr; both readings resolve to the bytes the shipped binary emits, and the ordering claims in the two new Exit-status rows ("never 13", "never 15 or 12") are true of the shipped control flow rather than merely asserted.
• [PASS] Trigger / description quality — no frontmatter or trigger surface in the diff; this is a contract table edit, not a SKILL.md change.
• [PASS] Cross-skill conflict / shadowing — write-pattern owns this contract; the diff touches no shared contract, marker namespace, or seam another skill reads. pattern/codes.ts still imports PRECONDITION_UNKNOWN from ../build/codes.ts, so the documented group alignment is unchanged.
• [PASS] Gate-invariant preservation — no gate invariant is in the diff's reach: the changed file is outside the live §CP set, adds only refusal seats, and removes nothing. Adding a refusal strengthens rather than weakens.
• [PASS] Contract implementation ticket (ADR 0248) — in scope by the file-list trigger (the diff changes a claude-plugins/fabrika/skills/*/contract.md), and the obligation it protects is already discharged: the implementation ticket Five fabrika pattern verbs are specified and none exists #5332 is closed, the five verbs are shipped on origin/main under packages/fabrika-cli/src/pattern/, and every row this PR adds was verified against that shipped source above. No verb is left specified-but-unbuilt, so no un-triaged build work owes a ticket.
• [PASS] deviation-disclosure — nothing undisclosed that this gate could see. Tier-M scan clean (0 suppression/skip lines, 0 removed-assertion lines); the Tier-R class-1 finding from round 2 (scope narrowing / different shape) is now disclosed under ## Deviations with its round tag, its Said/Did/Why, and a correct disposition, and the body no longer asserts any pre-repair state.

Read the PR head (§HEAD): the head SHA was resolved live via REST and re-confirmed unchanged before binding; all contract text and the shipped verb sources were read from c4f598eb… / origin/main via gh api raw reads, never the launched checkout's working copy. No working tree was switched (§RO).

All checks pass — 7/7 acceptance criteria and 6/6 rigor rows, including deviation-disclosure. This PR is merge-ready. review-skill does not merge — ship-it is the authorized merge step; merging will auto-close #5355 via Fixes #5355.

Verdict-written: 2026-08-10T21:43:36Z