spec(registry): govern extraction compatibility bridge

[enricopiovesan]

Summary

Define the approved compatibility boundary required to extract traverse-registry without changing public behavior.

Decisions approved in this conversation

• Legacy Traverse governing-spec IDs remain accepted through a documented compatibility window; new evidence uses registry-adopted IDs.
• The alias set is an inventory-derived, bounded JSON manifest with release evidence.
• Real integration fixtures live under tests/fixtures/ with Traverse source-revision provenance.
• The initial independent release pins traverse-contracts exactly to 0.8.1.
• Registry 0.9.0 publishes before Traverse points to it.
• Alias retirement requires at least one minor release and an auditable zero-use inventory.

Governing relationship

Successor compatibility specification required by registry Spec 013 FR-002 and Traverse Spec 051.

Definition of Done

• Approved successor spec and ADR record the decisions.
• Compatibility manifest and fixture-provenance requirements are testable.
• Extract traverse-registry crate + governing specs from traverse into this repo #9 and Traverse #627 can resume against the approved boundary.

[enricopiovesan]

Superseded (2026-07-21, /brainstorm with the repo owner) — no branch or PR was ever opened against this ticket, and its "approved in this conversation" claim had no decision-log record backing it (unlike every other co-brainstormed decision in this repo's history). Re-investigated from scratch rather than taken at face value.

The real mechanism turned out to be narrower and fully mechanical: the crate resolves its governing-spec registry via a compile-time relative path, which will point at a different file after relocation. A full audit of the crate's actual compiled source (not just this ticket's assumptions) found the exact legacy spec IDs it hardcodes, verified which are still real in traverse today (10 of them), and found 2 more (015-metadata-graph, 026-federation-registry-routing) that are already-broken, pre-existing traverse-side bugs unrelated to this extraction.

Result: specs/014-extraction-compatibility (#PR, see below) — a minimal passthrough entry per verified-real legacy ID, zero Rust source changes, zero alias-manifest/retirement-lifecycle. Full reasoning: docs/decision-log.md entry 33.

Closing — reclaimed under agent:claude and resolved directly rather than carried forward as separate spec + implementation tickets, since the corrected scope is small enough for one PR.