Add live lot memory schema

Author: traviscomber

db/migrations/007_live_lot_memory.sql

@@ -0,0 +1,12 @@
+create table if not exists lot_events (
+  id uuid primary key default gen_random_uuid(),
+  reception_id uuid not null references receptions(id) on delete cascade,
+  event_type text not null check (event_type in ('quality','production','note')),
+  title text not null,
+  detail text,
+  metrics jsonb not null default '{}'::jsonb,
+  created_by text not null,
+  occurred_at timestamptz not null default now(),
+  created_at timestamptz not null default now()
+);
+create index if not exists lot_events_reception_time_idx on lot_events(reception_id,occurred_at desc);