Api Points Transactions Summary Retrieve

GET /api/points-transactions/summary/ Get the caller's own organization's Respan Points balance + USD book value (mirrors /api/credit-transactions/summary/).

Own-org only — including superadmins. There is NO ?org= cross-org override (dropped to eliminate the cross-tenant leak / unknown-org bug class). The org is resolved via ProjectScopedQuerysetMixin's get_request_project_id(); an unresolvable own org FAILS CLOSED to a zero-balance 200 (consistent with the list endpoint's empty result), NOT a 404.

Response: { "unique_organization_id": "...", "points_balance": 1200.0, "usd_book_value": 12.0, "last_points_event_at": "..." # null when the org has no points }