Architecture review QRun-IO/qqq#1150 F5: qbit-marketing compiled against
assistant internals.
- New artifact qbit-assistant-provider-api with the provider SPI and
value types (same package names) and engine.ModelPricing; production
dependency jackson-annotations only. An ArchUnit test keeps it free of
assistant internals.
- AssistantProviderType's settings validation takes ProviderSettings
instead of the assistant_provider entity (documented in UPGRADE.md).
- qbit-assistant and the provider modules depend on the API artifact.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>