fix: correct EvidenceReference field name in bulk verification handler

[esthereze]

Summary

The BulkCheckInResult type in src/routes/verifications.ts declared its evidenceReference shape with an evidenceReferenceUrl field, but the authoritative EvidenceReference interface in src/services/evidence.ts uses referenceUrl. This caused TS2741: Property 'evidenceReferenceUrl' is missing in type 'EvidenceReference' when assigning the result of createEvidenceReference() to itemResult.evidenceReference.

Changes

src/routes/verifications.ts

• Import EvidenceReference from evidence.js and use it directly in BulkCheckInResult instead of an inline type with the wrong field name — resolves TS2741
• Fix AppError error-code mapping in the bulk handler to use error.code and error.status instead of the non-existent error.statusCode property (resolves TS2339)

src/tests/verifications.bulk.test.ts

• Add requireAdmin to the rbac.js mock so the module loads correctly (previously the suite failed to run at all)
• Add an error handler to the test app matching the production AppError response shape
• Add test: "evidenceReference in response uses referenceUrl field (not evidenceReferenceUrl)" — asserts evidenceRef.referenceUrl === REF_URL and evidenceRef.evidenceReferenceUrl === undefined

Test results

All 19 tests pass (previously the test suite failed to load due to the missing requireAdmin mock export).

Closes Disciplr-Org#993