feat(billing): add dual formulas, disable 10yuan gift, retry auto-renew

Turn off the low-balance 10 CNY signup bonus while keeping the 5 CNY
registration credit, split metering into independent formula A/B scopes,
and retry expired auto-renew subscriptions after recharge or hourly worker.

Co-authored-by: Cursor <cursoragent@cursor.com>

db.mjs

@@ -583,6 +583,12 @@ export async function migrateSchema(pool) {
     );
   }
 
+  if (!(await columnExists(pool, 'h5_users', 'billing_formula'))) {
+    await pool.query(
+      `ALTER TABLE h5_users ADD COLUMN billing_formula ENUM('A','B') NOT NULL DEFAULT 'A' AFTER low_balance_gift_granted_at`,
+    );
+  }
+
   if (!(await columnExists(pool, 'h5_user_sessions', 'goosed_node'))) {
     await pool.query(
       `ALTER TABLE h5_user_sessions ADD COLUMN goosed_node TINYINT UNSIGNED NOT NULL DEFAULT 0`,