docs: add N'KEMBA institutional reconstruction crosswalk

[riscas028]

Summary

Adds a non-normative crosswalk for N'KEMBA as a downstream institutional-reconstruction consumer of TRACE evidence.

The crosswalk:

• keeps TRACE references entries as pointers rather than attested evidence;
• separates runtime verification from authorization, operative-document, external-outcome, and adoption layers;
• states both what each input can satisfy and what it does not satisfy by itself;
• describes fail-closed consumer outcomes without adding fields or conformance requirements to TRACE;
• uses only the registered authorized-intent, approval-outcome, and behavior-trace relationship values;
• adds the page to the Crosswalks navigation.

Scope

Documentation only. No schema, wire-format, required-claim, registry, or conformance change.

Review context

Follows the venue and boundary guidance in #274 and the structure of the Acta crosswalk.

The contributor has reviewed the proposed text and can explain its intended mapping and boundaries.

Closes #274

[rajnisht7]

@riscas028, in the references section the link is spec/trace-v0.2.md#312-external-references whereas the heading is #### 3.1.2 references: facts this record points at, hence the anchor should be #312-references-facts-this-record-points-at

[riscas028]

Fixed — thank you for catching that. The section 3.1.2 reference now points to #312-references-facts-this-record-points-at.

[imran-siddique]

Review/test follow-up on f21e66a9156a.

The crosswalk keeps references as pointers and institutional verdicts outside TRACE conformance. The example does not promote a verified runtime into a proved institutional outcome. CI and CodeQL both ran and passed after release. Prefer this scoped version over the overlapping #275; both add the same document and navigation entry, so they should not both merge.

Full local python -m pytest -q (Windows, Python 3.12, existing review environment): 5 failed, 1162 passed, 1 skipped in 10.98s.

The five local failures are the four generated-fixture byte comparisons and test_every_schema_in_the_repository_is_classified, matching the Windows newline/path-separator failures seen across these branches. The hosted Linux suite is green; the local suite is not.

Contribution requirement still outstanding: these commits have no Signed-off-by: trailer: f21e66a9. Please have the respective commit authors add their own DCO sign-offs, including merge commits, then request review of the resulting head.

Fresh workflow evidence: 34034168524 (success), 34034168613 (success).

[riscas028]

Updated the head to address the outstanding contribution requirement. The anchor fix is unchanged, and the replacement head commit now carries the author DCO trailer (Signed-off-by). The scoped #291 remains the candidate; I am closing the overlapping #275 as requested. Please re-review the resulting head when convenient.

[imran-siddique]

Re-reviewed signed head 026f419. Its tree is identical to the reviewed crosswalk, every commit now has a DCO sign-off, and fresh CI (Python 3.11/3.12) and CodeQL passed. No unresolved review threads.

The crosswalk keeps registered references as pointers, requires independent evaluation of institutional evidence, and explicitly avoids adding TRACE conformance requirements. The author closed overlapping #275, leaving this as the single candidate.