LRU cache with TTL

Implement a cache that combines LRU eviction with per-entry TTL. Process operations: ["put", now, key, value, ttl] inserts/updates key=value at time `now`, expiring at now+ttl (alive while query time < now+ttl), and marks it most-recently-used; ["get", now, key] returns the value if present and not expired (and marks it most-recently-used), else -1. Capacity is `capacity`: when a put would exceed capacity with a new key, first drop any currently-expired entries (as of `now`); if still over capacity, evict the least-recently-used live entry. A put that updates an existing key never triggers capacity eviction. Timestamps are non-decreasing. Return the list of get results in order. capacity is a positive integer.