[jonahgabriel]

Summary

Net-new OCC companion providing the Evidence-Source durable receipt for omnibase_core PR #1420 (OMN-14331 — retire the frozen models→validation import-layering back-edge, 18 edges, epic OMN-3210).

Authored by an independent adversarial verifier (verify-1705) that did NOT implement the product code, per no-self-authored-evidence (OMN-14055).

Independent verification (product head 26120779733e48a0c7112d0f64b2e59135800ad2, PYTHONPATH cleared)

• Oracle: env -u PYTHONPATH uv run lint-imports → 4 kept, 0 broken (4076 files, 10339 deps) with BOTH models.** -> validation ignore lines DELETED from .importlinter.
• Negative control (real-severance proof): adding a throwaway models/_negative_control_zzz.py importing omnibase_core.validation.validator_topic_suffix (ignore lines still removed) turned "Models must not import behavioral/orchestration layers" BROKEN (3 kept, 1 broken) — the oracle genuinely catches the edge, so the green result is real severance, not wildcard-masking. Removal restored 4 kept/0 broken. Worktree left clean.
• Behavior parity: a 37-input adversarial harness comparing OLD validate_topic_suffix (origin/dev) vs NEW check_topic_suffix → 0 mismatches on validity AND exact error strings across valid, whitespace, case, env-prefix, segment-count, kind, kebab, version, control-char cases. Re-export shims (validator_topic_suffix, validator_utils, runtime_ops_verb_loader, validation/__init__) preserve the historical public API.
• Grep: zero real omnibase_core.validation import statements remain under src/omnibase_core/models/ (remaining hits are docstrings/comments; none TYPE_CHECKING-hidden).
• Tests: 380 passed (topic_suffix, runtime_ops_verb_loader, hex_color, topic_taxonomy).
• mypy --strict clean on all 30 changed files; the 5 import-not-found (redis/omnibase_spi) are pre-existing in untouched files (backend_cache_redis.py, service_protocol_auditor.py), not introduced. ruff clean.

Files (3 net-new)

• contracts/OMN-14331.yaml — 2 dod_evidence items (dod-omnibase_core-pr-1420, dod-occ-self).
• drift/dod_receipts/OMN-14331/{dod-omnibase_core-pr-1420,dod-occ-self}/command.yaml.

dod-omnibase_core-pr-1420 binds to product PR #1420 (pr_number + commit_sha). dod-occ-self self-binds via C1 commit SHA 57b78b84d9b23f604bbf88b8ac920d55b09df543. contract_sha256 = raw-bytes sha256 of the yamlfmt'd contract (0d02b279…).

Do not merge before omnibase_core #1419 per the shared seam-family landing order (Codex owns the merge).

Evidence-Ticket: OMN-14331