Bump version to 1.4.1 and tighten client handling

src/db.js

@@ -31,6 +31,13 @@ async function addColumnIfMissing(pool, tableName, columnName, columnDefinition)
   await pool.query(`ALTER TABLE \`${tableName}\` ADD COLUMN \`${columnName}\` ${columnDefinition}`);
 }
 
+async function pruneStaleOnboardingDevices(pool) {
+  await pool.query(
+    `DELETE FROM player_onboarding_devices
+     WHERE modified_at < (CURRENT_TIMESTAMP - INTERVAL 1 MINUTE)`
+  );
+}
+
 async function ensureSchema(pool) {
   await pool.query(`
     CREATE TABLE IF NOT EXISTS canvas_sizes (
@@ -262,5 +269,6 @@ async function ensureSchema(pool) {
 
 module.exports = {
   createPool,
-  ensureSchema
+  ensureSchema,
+  pruneStaleOnboardingDevices
 };