List sandbox valuation and appraisal cases

Returns deterministic sandbox case, property-fact, comparable-evidence, inspection, professional-review, and handoff summaries when the authenticated automation client has valuation_appraisal.cases.read. External URL: /v1/valuation-appraisal/current/cases. Current Next.js implementation path: /api/platform/v1/valuation-appraisal/current/cases. This read-only route does not require Idempotency-Key and never exposes exact addresses, unit identifiers, ownership identity, client or lender contacts, access instructions, raw comparable records, adjustment notes, raw reports, credentials, write controls, or live provider integrations. Official valuation records, inspection scheduling, report issuance, client or lender handoffs, and comparable-evidence writes remain explicitly deferred and professional review is always required.