Spec v0.9.0 compliance

Tracks [spec v0.9.0](https://github.com/open-feature/spec/releases/tag/v0.9.0) compliance (static-context). finally-with-details already done (close stale #56/#57).

- [ ] #99 Hook data
- [ ] #101 Telemetry utility ([Appendix D](https://openfeature.dev/specification/appendix-d))
- [ ] #97 Shutdown
- [ ] #115 Isolated API instances
- [ ] #121 Domain in provider init (umbrella: #96 Domains)
- [ ] #105 InMemory provider + e2e harness
- [ ] Logging hook

- [ ] Provider lifecycle event ownership (race-condition fix): add opt-in marker so providers emit their own `PROVIDER_READY`/`PROVIDER_ERROR`/`PROVIDER_RECONCILING`/`PROVIDER_CONTEXT_CHANGED`; SDK derives status from the provider event stream and keeps + deprecates the legacy synthetic path; update first-party providers ([spec 5.3.5](https://openfeature.dev/specification/sections/events#requirement-535), [provider status 2.8](https://openfeature.dev/specification/sections/providers#28-provider-status), [Appendix E](https://openfeature.dev/specification/appendix-e))

Start by reading the linked Spec v0.9.0 requirements and the referenced issues #99, #101, #97, #115, #121, and #105. Map the remaining checklist items, including logging and provider lifecycle ownership, to the SDK and first-party providers; done means the Swift SDK meets the listed v0.9.0 compliance requirements.

Written by the indexing model from the issue text.