Read retained governance decisions by evidence phase

Returns recent retained decision evidence, optionally filtered by phase. A row records what governance evaluated and decided at that phase; it does not prove an invocation, payment, settlement, provider call, receipt, or agent task. Use correlation_ref to join phase evidence where present and use durable invocation and receipt/settlement surfaces for outcomes. total is the true count matching the supplied filters, while returned is the bounded number of recent rows in decisions. The summary maps describe only those returned rows. Results use keyset pagination ordered by created_at DESC, id DESC. The first request fixes the newest sort-key upper bound, so rows above that bound cannot shift later pages. This is not a database transaction snapshot: normal retention expiry, and a concurrent insert sharing the boundary timestamp but sorting below its ID, can still alter the eligible set. SQLite records default decision timestamps at one-second resolution, so shared timestamps are expected during bursts. next_cursor is opaque and bound to the active filters. limit defaults to 50, is defensively capped at 500, and rejects malformed, fractional, zero, or negative values.