Auto-creates missing plans, assigns users to matching tiers, and reports to Telegram.
Auto-assign: every user is matched to a plan whose price
equals their users.expected_amount. Missing plans are created
automatically. The Fallback Plan below is only used if a tier can't be
matched (shouldn't happen).
Removes the tables created by the migration
(isp_accounts, subscription_plans).
users and licenses are never touched.