Spec v0.9.0 compliance

[toddbaert]

Tracks spec v0.9.0 compliance.

• Add Hook Data Support #384 Hook data (spec 4.6)

• Supply the bound domain to provider initialization #518 Domain in provider init

• Bump test-harness submodule to v0.9.0

• Provider lifecycle event ownership (race-condition fix): add opt-in marker so providers emit their own PROVIDER_READY/PROVIDER_ERROR; SDK derives status from the provider event stream and keeps + deprecates the legacy synthetic path; update first-party providers (spec 5.3.5, provider status 2.8, Appendix E)