Headline counters for the Terraform -> OpenTofu migration. Account-wide: these
ignore any predicates the queue view has applied, so a filtered list will not
add up to them. Per-state counts that follow the filter come from
openTofuMigrationQueueSearchSuggestions instead.
- eligibleToMigrateStacks eligible for migration that are not queued right now — exactly what openTofuMigrate(target: OpenTofu) with no predicates would enqueue, and the same cohort openTofuMigrateSearch(target: OpenTofu) lists. Covers stacks with no queue entry as well as ones whose last attempt ended in a terminal ROLLEDBACK or FAILED state, since those can be re-driven.
- queuedToMigrateQueue entries in state TO_MIGRATE: picked up, not yet processed.
- queuedToRollbackQueue entries in state TO_ROLLBACK: rollback requested, not yet processed.
- migratedQueue entries in state MIGRATED: successfully migrated to native OpenTofu and not rolled back since.
- rolledBackQueue entries in state ROLLEDBACK: rolled back to the legacy Terraform shape. Normally also counted in eligibleToMigrate, since a rolled-back stack can be migrated again.
- failedQueue entries in state FAILED: the migration or rollback errored, see the entry's note. A failed *migration* is normally also counted in eligibleToMigrate, since re-issuing openTofuMigrate re-drives it. A failed *rollback* is not: the stack still has vendor OpenTofu, so it belongs to the rollback cohort, not the migration one. FAILED is a single state for both directions, so this counter and eligibleToMigrate never have to move together.