Constant OUTCOME_RETENTION_LMIDS 

pub const OUTCOME_RETENTION_LMIDS: i64 = 512; // 512i64

Retention bound for ROOM_MUTATION_OUTCOMES_TABLE rows, by lmid distance — never by time (Slice I-ii). When a room flush advances a (doc, client) ledger row to lmid, rows with mid ≤ lmid − K prune in the same transaction. K = 512 mirrors the room shell’s per-client recorded-outcome FIFO cap (MAX_RECORDED_OUTCOMES_PER_CLIENT = 512, packages/room/src/shell.ts) — the two ends of the outcome-resolution surface degrade at the same depth. The accepted loss class is the H-v one: a pruned mid reads as applied through the daemon, exactly as an evicted map entry re-answers with silence on the room socket; a client is only ever that far behind its own ledger with a backlog ≥ K in flight.