Refine monthly close cleanup

backend/src/migrations.ts

@@ -295,6 +295,16 @@ export async function migrate() {
     );
   `);
 
+  await query(`
+    CREATE TABLE IF NOT EXISTS ticket_day_billing_acknowledgements (
+      ticket_id BIGINT NOT NULL REFERENCES tickets(id) ON DELETE CASCADE,
+      user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+      day DATE NOT NULL,
+      acknowledged_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+      PRIMARY KEY (ticket_id, user_id, day)
+    );
+  `);
+
   await ensureClosureOwnership("ticket_month_closures", "month", ["ticket_id", "month"], adminId);
   await ensureClosureOwnership("month_closures", "month", ["month"], adminId);
   await ensureClosureOwnership("ticket_day_closures", "day", ["ticket_id", "day"], adminId);
@@ -309,6 +319,7 @@ export async function migrate() {
   await query("CREATE INDEX IF NOT EXISTS idx_sessions_billing_status ON sessions(billing_status);");
   await query("CREATE INDEX IF NOT EXISTS idx_ticket_day_closures_day ON ticket_day_closures(day);");
   await query("CREATE INDEX IF NOT EXISTS idx_ticket_day_billings_user_day ON ticket_day_billings(user_id, day);");
+  await query("CREATE INDEX IF NOT EXISTS idx_ticket_day_billing_ack_user_day ON ticket_day_billing_acknowledgements(user_id, day);");
   await query("CREATE INDEX IF NOT EXISTS idx_recurring_billings_user_active ON recurring_billings(user_id, active);");
   await query("UPDATE recurring_billings SET active = true WHERE active = false;");
   await query(`