fix: configure postgres idle timeout and connection recycling for Railway

Railway proxy closes idle DB connections after ~60s, causing
CONNECTION_CLOSED errors on stale sockets. Set idle_timeout=20s and
max_lifetime=5m so postgres-js recycles connections before they die.

Also fix sendCommand to fall back to persistent device ID on reconnect.

web/src/lib/server/db/index.ts

@@ -5,6 +5,10 @@ import { env } from '$env/dynamic/private';
 
 if (!env.DATABASE_URL) throw new Error('DATABASE_URL is not set');
 
-const client = postgres(env.DATABASE_URL);
+const client = postgres(env.DATABASE_URL, {
+	idle_timeout: 20,
+	max_lifetime: 60 * 5,
+	connect_timeout: 10
+});
 
 export const db = drizzle(client, { schema });