“The album path must INHERIT the Forge's full capability set — a second entry point inherits nothing automatically.”
Surfaced:Builds 3539-3543 (Constraint Fidelity + Opera/Language WAR ROOMs, 2026-06-02). Across one session the same gap recurred FOUR times: the album fan-out — which skips preforge — silently lacked banned-word extraction (B3539), structural-form variety (B3540), target-language capability (B3541), and a shared world canon (B3542), each a capability the single interactive Forge either had or gained. The operator's all-Italian opera "La Nona Campana" came back as English pop songs with anachronistic, renamed characters because none of language / world-canon / form / bans reached the album generator. Each fix was the same shape: extract the signal at the bible stage, thread it bible → generation fan-out → refine. Ratified B3545 with the check:album-capability-parity gate.
The anti-pattern this names
A pipeline with two entry points to the same core — here the single interactive Forge and the headless album fan-out — where the second is a stripped-down path that skips the first's preprocessing (preforge / brief extraction). Every capability added to the rich path is invisible to the stripped path by default. The gap is SILENT because the stripped path still produces output; it just quietly ignores the constraint (writes English instead of Italian, pop instead of opera, renames the cast). The signature: a capability demonstrably works on /forge but is absent on the album, and the absence is discovered only by an operator running a real album — never by a test, because no test asserted parity.
The check
Before declaring a Forge capability shipped, ask: does the ALBUM path carry it too — through the bible (extraction + plan_json STATE), the generation fan-out (the forgeAlbumTrack call), AND the refine re-forge? Capability parity is enforced by check:album-capability-parity (B3545): a canonical list of album-inherited capabilities (forbiddenLanguage, language, form, setting, characters) each asserted present at all three plumbing sites (album-track-forge.ts, album-generate-fn.ts, album-track-refine.ts). Adding a capability at one site without the others fails the gate; adding a new album capability means adding it to the canonical list + all sites. Relationship to SA#29 ("genre signal is plumbed as STATE, not parsed from TEXT"): SA#36 is the META-level sibling. SA#29 governs HOW a signal travels (typed state, not prose) — it is per-signal, within one path. SA#36 governs WHETHER a capability reaches the second entry point at all — it is per-capability, across entry points. SA#29 is the plumbing technique; SA#36 is the parity obligation. Canonical phrasing: BRAND.sacredAccident36. Full WAR ROOMs: docs/WAR-ROOM-CONSTRAINT-FIDELITY-2026-06-02.md + docs/WAR-ROOM-OPERA-LANGUAGE-2026-06-02.md.
Share this discipline
“A second entry point inherits nothing. Every capability the Forge gained — banned-words, language, structural form, world canon — was silently absent from the album path until plumbed, four times in one session. Parity is the price of a second door. — Sacred Accident #36”
Why this gets its own permalink
Each Sacred Accident is a discipline this codebase operates under — a rule named on the public record, enforced in the build pipeline, and cited in every commit that advances the moat it protects. Permalinking each one turns the discipline into a teaching artifact: a buyer or partner who reads this page can cite the exact principle we operate under without grepping our docs.
Canonical phrasing: BRAND.sacredAccident36 · Doc: docs/SACRED-ACCIDENTS.md