Move old migrations (20260109 through 20260817) to _archived/ and add a
single consolidated migration (20260818_024510). Update the migrations
index to reference only the new migration.
Migration 7 originally bundled tickets DDL with pending schema drift, which made it fail against prod (no tickets objects existed there). Split into a stripped migration 7 (no tickets statements) and a new tickets-only migration 8 that creates enum_tickets_* types, ALTER TYPE ADD VALUE for 'tickets' + 'ticket:*' muted-type values, tickets and tickets_activity tables, and the payload_locked_documents_rels.tickets_id column + FK + index. Migration 8's .json snapshot is the new forward baseline for migrate:create (verified via zero-diff probe). Applied to prod: m1-7 baselined as batch 1, m8 applied as batch 2.
