Enforce 10j's verified gaps (schema-hardening change):
- Migration 00010: partial unique indexes for one default pool and one
primary assignment per workspace, plus CHECKs pinning
pool/provider/subscription vocabularies and provider lifecycle
timestamps.
- Workspace creation shares a transactional provisioning function;
extension validates its target pool; last-tier deletion of a defaulted
ladder is guarded; signup completes plan-less on a broken ladder.
- Boot asserts integration slug parity and validates declared config
enums; Stripe invoice amounts are range-checked; domain cancellation
runs a final evidence probe; rule authoring is additive-only.
cgalo5758
ad7a219adf