Recent updates sheet (Feature 21) (#176)

Co-authored-by: orchestrator-agent <20+orchestrator-agent@code.cubecraftcreations.com>

migrations/queries/settings.sql

@@ -154,3 +154,11 @@ RETURNING *;
 UPDATE chat_settings
 SET last_test_at = ?, last_test_status = ?, updated_at = ?
 WHERE id = 1 AND webhook_url_ct = ?;
+
+-- name: MarkUpdatesSeen :execrows
+-- Moves updates_seen_at forward to seen_at; affects no row when it is
+-- already at or after seen_at, so it never moves back. It is not a settings
+-- edit: updated_by and updated_at are left as they are.
+UPDATE household_settings
+SET updates_seen_at = CAST(sqlc.arg(seen_at) AS TEXT)
+WHERE id = 1 AND (updates_seen_at IS NULL OR updates_seen_at < CAST(sqlc.arg(seen_at) AS TEXT));