2fbdbf5ab0
Three bugs caused trial subscriptions to be auto-renewed without a tariff at arbitrary prices: 1. try_auto_extend_expired_after_topup: is_trial guard used truthiness check — NULL (legacy rows) passed as falsy. Changed to `is_trial is not False` (NULL-safe). 2. Multi-tariff branch: `not s.is_trial` treated NULL as not-trial. Changed to `s.is_trial is False`. 3. Telegram bot autopay toggle: no is_trial guard — users could enable autopay on trial subscriptions. Added trial check before enabling.