* refactor(relay): stop creating three tables nothing writes
relay_confirmable_splices, relay_cell_drain_attempts and
relay_migration_leases are created at every boot and referenced nowhere
else on main except tests. In production all three hold 0 rows and
pg_stat_user_tables shows 0 inserts, 0 sequential and 0 index scans since
the 2026-09-28 stats reset.
This removes them from the schema and the transaction-phase table, and
drops the test references. It does not drop them: an older image still
runs CREATE TABLE IF NOT EXISTS at boot, and a drop racing that create can
fail the older boot's schema step. A follow-up can drop them once no image
that creates them can be rolled back to.
* docs(relay): note the account-erasure prerequisite for dropping retired tables
Phase 6 of the relay split: the relay's deploy/operate surface moves under cloud/ with 24 cloud-* workflows gated on ORCA_CLOUD_OPERATIONS_ENABLED, the Cloud SQL rollout lease action, the relay Terraform root (dual-accept identities for both repositories), scripts, docs, CODEOWNERS, and a terraform validate job in Cloud Verify.
OrcaWinandOrcaWin
Jinwoo Hong