feat(ci): ai admission fixture corpus for publish-time parity (#627)

[enricopiovesan]

Summary

Closes #627. Adds a registry-owned fixture corpus for the ai admission rules: accept/reject cases plus a test proving capability_validation.py agrees with every one. traverse-cli capability publish will vendor a pinned copy, so it can reject the same contracts locally before a registry PR exists (traverse Decision 109, traverse-framework/traverse#1459 / traverse-framework/traverse#1597).

Governing Spec

• 001-registry-foundation
• 002-capability-validation
• 026-model-rights-compliance

Project Item

• Admission fixture corpus for ai/model-attribution rules (CLI parity, traverse Decision 109) #627

What Changed

• scripts/ci/fixtures/ai_admission_corpus.json: 103 fixtures, corpus_version 1.0.0.
  • Each fixture has a tier (contract_decidable | ci_only), an evaluated_as (newly_added | existing), and the sorted set of expected CI error codes.
  • Coverage:
    • FR-017 shapes, including legacy vs. new contracts, ai: null, and mixed arrays;
    • immutable pins;
    • SPDX syntax;
    • the full spec 026 rights record;
    • evidence-file shape;
    • derivation;
    • data obligations;
    • rights_change;
    • the network and cross-file ci_only cases.
• scripts/ci/tests/test_ai_admission_corpus.py runs the exact CI code paths. It is wired into the required capability-validation job.
• validate_ai_declaration is split out of validate_contract, with no behaviour change. The existing 210 tests pass unchanged.
• Bug fix: the corpus surfaced four TypeError: unhashable type crashes. A list or object given as a rights enum, verification.status, a derivation.transformations[] entry, or data_obligations[].kind crashed CI instead of failing with the documented code. All four are now guarded and covered by fixtures.
• docs/model-rights.md: a new "Admission fixture corpus" section, with the rule that changing an ai rule means updating the fixtures in the same PR.
• Decision-log entry 129.

Validation

• python3 -m unittest scripts/ci/tests/test_ai_admission_corpus.py: all 103 fixtures agree
• python3 -m unittest scripts/ci/tests/test_capability_validation.py: 210 tests pass
• The test fails when a fixture's expected codes are changed
• The four crash inputs raise TypeError on main's validator and fail cleanly with this change
• pre_pr_check.sh

🤖 Generated with Claude Code