Process a sequence of timestamped operations for a single-threaded GPU credit manager. Rules: - Every user starts with 0 credits. - `user_caps[user]` is that user's maximum balance. If a user is missing from `user_caps`, their cap is unlimited. - `user_org[user]` gives the user's organization. If a user is missing from `user_org`, they have no organization. - `org_caps[org]` is the maximum total active balance across all users in that organization. If an organization is missing from `org_caps`, its cap is unlimited. - Operations are given in nondecreasing timestamp order and are processed atomically. - Credits are stored in lots. A granted lot may expire at a specific timestamp. Before processing any operation at time `t`, all remaining credits from lots with `expire_time <= t` disappear. - When consuming credits, always consume from the earliest-expiring active lots first. Non-expiring lots are treated as expiring last. - `grant` and `refund` are partially applied if necessary: add as many credits as possible without violating the user cap or the organization cap. - Balances can never go negative. - `topK(k)` returns up to `k` users with positive balances, sorted by balance descending, then by user name ascending. Implement `solution(user_caps, user_org, org_caps, operations)` and return a list containing the result of every operation in order. Operation formats: - `('grant', t, user, amount, expire_time)` -> return the integer amount actually added. `expire_time` is an integer timestamp or `None`. - `('refund', t, user, amount)` -> return the integer amount actually added. Refunded credits never expire. - `('consume', t, user, amount)` -> return `True` if the full amount was consumed, otherwise `False`. - `('get', t, user)` -> return the user's current active balance. - `('topK', t, k)` -> return a list of `[user, balance]` pairs.