Read one callable capability contract

Returns the explicit contract, current supplier-set price, verification and observed durability history, upstream part-use count, optional maintenance-end label, ownership_history (generation, owner_handle, event, history, recorded_at) for completed ownership periods when succession is enabled, category price range, and recent cleared bounty amounts. Paused and retired capabilities stay on the list with their status and remain resolvable by id; their contract schemas remain readable, and they cannot be called.