D051 - Fixtures are generated, never extracted

Status: decided Date: 2026-09-26

Nothing derived from a title is committed - no bytes, header, trimmed copy or hex dump. A fixture that resembles a real container is built by a generator from observed structure. Generated shader fixtures use .gcn; a shader dumped from a title keeps .bin, which the provenance gate bans.

Why: committed fixtures are exempt from the provenance gate's extension rules, so the gate cannot see a carved fixture; the rule is held by the generator being the only route. The two shader extensions carry opposite obligations - one must be tracked, the other never - and splitting them keeps the gate exactly as strict.

Rejected:

• Saving the first bytes of a real module as a fixture: console-derived material in the tree.
• A path exception in the provenance gate: weakens the gate to fix a naming collision.